The Reaction Steps in the Conversion of 2,3-Di-p-Toluenesulfonoxybutane to 2,3-Diacetoxybutane Citation Mitchell, Fern Wood, Jr. (1946) The Reaction Steps in the Conversion of 2,3-Di-p-Toluenesulfonoxybutane to 2,3-Diacetoxybutane. Master's thesis, California Institute of Technology. doi:10.7907/r83p-vm58. https://resolver.caltech.edu/CaltechTHESIS:04182025-220746373 Abstract No abstract. Item Type: Thesis (Master's thesis) Subject Keywords: (Chemistry) Degree Grantor: California Institute of Technology Division: Chemistry and Chemical Engineering Major Option: Chemistry Thesis Availability: Public (worldwide access) Research Advisor(s): Lucas, Howard J. Thesis Committee: Unknown, Unknown Defense Date: 1 January 1946 Record Number: CaltechTHESIS:04182025-220746373 Persistent URL: https://resolver.caltech.edu/CaltechTHESIS:04182025-220746373 DOI: 10.7907/r83p-vm58 Default Usage Policy: No commercial reproduction, distribution, display or performance rights in this work are provided. ID Code: 17163 Collection: CaltechTHESIS Deposited By: Benjamin Perez Deposited On: 21 Apr 2025 19:04 Last Modified: 21 Apr 2025 19:20 Thesis Files PDF - Final Version See Usage Policy. 7MB Repository Staff Only: item control page

The Reaction Steps 1n the Conversion of 2,3-Di-p-toluenesulfonoxybutane to 2,3-Diacetoxybutane Thesis by Fem Wood Mitchell, Jr. In partial fulfillment of the requirements for the De~ree of Master of Science California Institute of Technolo~y Pasadena, California 1946 Acknowlede;ment The help ,and guidance of Professor Howard J. Lucas during the progresa of this research is sincerely apprecia.ted, as a re the helpful sugges t1ons of Df• Saul W1nste1n. - 1 - When replacement reactions take place in organic molecules which have a functional group on the carbon adjacent to the one affected, it hae been shown that often this adjacent group influences the course of the reaction. Thia effect may be exerted inductively on the seat of the replacement as in the reaction below: RX + -HOR ► ROR + me. In this reaction R ie methyl, ethyl,iaopropyl or tertiary butyl. W1 th methyl, ethyl and iaopropyl, reaction goo• by an SN2 mechanism with successively diminishing speeds and with iaopropyl and tertiary butyl by an SN1 mechanism with increasing speeds. Isopropyl undergoea reaction by both mechanisms aimultaneouely. 1 • 2 On the other hand the effect of an adjacent group may make itself felt by the actual formation of bonds between the carbon on which aubet1tution is taking place and the adjacent group, to form a cycli~ intermediate. The existence of cyclic bromonium a.nd chloronium ion intermediates has ,· · already been 4 shown. 3 • The present investigation was undertaken to show the existence of a cyclic ortho-eater intennediate in the case of aubati tution reactions with an acetoxy -@;roup on an adjacent. oarbon atom. The reaction studied wae the replacement of the 2-tolueneaulfonoxy group by the acetoxy group. The compound• - 2 - studied were the E-tolueneeulfonatee and acetates of 2, 3butaned1ol. yH3 rH3 CH-O-COCH3 I CH-O-COCH3 CH-O-S02C7H7 I H-O-COCH 3 1 CH3 I CH 3 2-acetoxy-3-p- 2,3-diacetoxybutane tolueneaulronoxybutane TH3 H-O-S02C7H7 2CH3COO 1 1H-O-S02C7H7 .,,, - CH 3 2,3-a1-p-toluene- - - - if>-, 1H3 CH-O-COCH3 I CH-O-COCH3 I CH3 2,3-diacetoxybutane sulfonoxybutane At the same time that this investigation was being carried out, roughly paralleled investigations of the acetatem and p-tolueneeulfonates of cyclohexanediol were being - carried out elsewhere. 5 • 6 The cyclic structure of the cyclohexane derivatives introduces certain extraneous structural effects which are not present 1n the butane series; for example, it is possible for a neighboring group on a cyclohexane molecule to form a bieyclic intermediate in the replacement reaction only when starting with a trans cyclic compound which will give a.£!.! bicyclic intermediate. 7 • 8 However, the resulte of the two investigations are mutually confirmative. When~ 2,3-di-E-toluenesulfonoxybuta.ne is heated with potassium acetate in glacial acetic acid under anhydrous - 3 - condi tione, the two E-toluenesulfonoxy group ■ are replaced by acetoxy groups with predominant inversion of configuration ( 100% ~ ~ 86% dl). Furthermore when erythro 2-1:.cetoxy- 3-£-tolueneeulfonoxybutane is treated under the same conditions it yields the d1acetoxy compound with almost complete retention of configuration. Since the 2-acetoxy-3-£-toluenesulfonoxy- butane 1s an intermediate in the first reaction these results localize the inversion at the carbon from which the first sulfonoxy group is displaced. CH~ I 0 H COS02.C7H1 I I Hco SOLC1H1 HC O SOa_C.71./7 I CH"!> CH~ l ► HCO~CH:, ➔ I CH,eOf M CH3,0CH CH1 CH3 Ciji I ]I 11[ I o I The reaction of acetate ion with I to give II presumably goes by a typical SN2 replacement mechanism and gives one inversion. If the carbon be~ring the remaining eulfonoxy ~roup were unaffected by the adjacent acetoxy group, replacement on it would be expected to take place in an identical manner giving another inversion. However, the ne15hboring acetoxy group does affect the replacement and the second stage of the reaction, from II to III, goes with either zero or an even number of inversions. The most likely mechanism is that proposed by Winste1n8 , involving formation of a cyclic intermediate (IV), an eeter of ortho-acetic acid. IY Ite formation would involve one inversion and its reaction with acetate ion · to give the diacetate would involve another inversion, giving an overall effect of retention of configuration. The likelihood of the formation of thi s intermediate is emphasized by the etrain-free ring and the possibility of resonance between the two equivalent forms. Further evidence of the existenee of this cyclic intermediate would be provided if the action of acetate ion on optically active threo 2-acetoxy-3- £-toluenesulfonoxybutane under . the same conditions as above would brin~ about eomplete raGemization. Time did not permit this experiment to be carried out; but this racemization has been observed in a closely related reaction, the action of silver acetate on optically active l-acetoxy-2-bromocyclohexane 8 • Furthermore an ortho-ester (V) has been isolated from the reaction mixture of the solvolysis of l-acetoxy-2£-toluenesulfonoxyayclohexane with ethano1 6 • y - 5 - When the reaotion of the meso di-£-toluenesulfonoxybutane with acetate ion to give 2,3-diacetoxybutane takes place in a mixture of aeetie acid, potassium acetate and one mol of water per mol of ester, the product is ~o.!?~'3--.:.a 1a.~:i:-'19~y:lfttJait.o.,,-<' .. Under the same conditions the conversion of 2-acetoxy-3-£toluenesulfonoxybutane (II) to 2,3-diacetoxybutane (IV) goes with almost complete inversion ( 100% ~ - + 96% dl). CH') I Hf O CJ.ll I C~ g Cf J-/ CH'?, I s~c.ru, __.,. Hf 6 so,_c,u, O HCO S01,.C7H7 ~ Cl\~ O~H CJ¼~ CH~ I E C H3i0f H :n CH~ From this it is seen that the first sta~e of the reaction, from I to II, is unaffected by the presence of water but the second stage, from II to VI, is markedly affected by water. The second stage of the reaction, that from II to VI, has been explained9 as ~oing through the followine; steps: c~ c~ H cos0a,c,N1 I H"lC OCH ~C ,to-Cli o > cu-cj',i. -~ I *'C-CH I c~ c~ IL IT c~, I CJi., I H C> CH HO XH I C"--, "c..c a /t I cu3 "SlI1I. ► ► CJ+,~O~H CH~ IX: - 6 - Even in the preaenee of water the cyclie intermediate IV is assumed to be formed. If water is present, water adds at the starred carbon, and a proton drops off to give the orthomonoacetate (VIII) which then rearranges to ~ive the normal monoaeetate (IX). Th.en, under the conditions of the experimen~, about half of the monoaeetate is acetylated to give the diacetoxybutane (VI). In the absence of water there is direct attack by acetate ion on either the c2 or c3 carbon of the butane chain of intermediate IV which gives rise to an inversion and yields the diaeetoxybutane directly. It would have been of interest to carry out the solvolysis of an optieally aetive 2-acetoxy-3-£-toluenesulfonoxybutane with both anhydrous acetate and acetate in the presence of water. If the reaction does go through the cyclic intermediate IV, there would be complete racemization in both cases. In order to prepare active butanediol the di-o,- )camphoraulfonoxybutanee were preparedo Three crystalline species of the di- \d :; -eamphorsulfonates of dl-butanedi•o1 were isolated. Their physical properties are shown in Tabler. Table I Configuration of original ~lyeol oe.2i [oc.]2i Oc 0 0 dl 42 2.50 41.0 £!. 105 2.58 60.8 dl 149 1.57 37.9 meso 120 1.98 46.4 m.p. - 7 - Enough of these materials to permit saponification and isolation of the .active glycols had not been prepared when this investigation was suddenly terminated. - 8 - Experimental !!!..!!!2.-2,3-Butanediol. -- The crude 2,3-butanediol was that of the Lue1dol Company prepared by the action of ~ bacter areo~enes on sugar. ~ It is a mixture of about 90% and the rest dl with a preponderenee of one of the forms to ~1ve a positive rotation. A five pound bottle of the viscous liquid glycol mi~ture was seeded with crystalline ~ - 2 , 3butanediol and allowed to stand for several months at room temperature to inerease the size of the crystals. Then the liquid was drained from the crystals, care being taken to exelude moisture from the glycol which is highly hygroscopie. This was aceomplished by replacin~ ·the glass stopper of the bottle eontainin~ the glycol with a rubber stopper fitted with a drain tube and a vent tube (fig. 1) and inverting the bottle on a 2-liter suction flask with a drying tube atLached to the side arm. The rubber stopper resting on the lip of the flask made an effective seal and the draining proeeeded very satisfactorily. After 48 hours the draining was eomplEilte and the crystalline material remaining had a melting point of 30.4-32.0°. - The mixed melting point curve of the 2,3butanediols lO indieates that this material was 96% meso ~ly001. The erystalline glycol was washed with a small amount of anhydrous isopropyl ether and then recrystallized from that solvent, us1n~ enough ether to prevent the formation of a se@ond liquid phase. The recrystallized glyool was distilled - 9 - under reduced pressure, b.p. 80°/10 mm. 0 One recrystallization . gave ~a product melting at 33.8, which is 99.4% ~ and two recrystallizations gave a product melting at 34.0°, whieh is 99.6% meso. erythro-3-Aoetoxy-2-butanol. -- To 90 g. (1.0 mol) of 99.6% ~ ~lycol (m.p. 34.0°) were added 102 g. (1.0 mol) of freshly distilled acetic anhydride and the mixture was cooled 0 ~o O • One drop of sulfuriG acid was added and the flask eontaining the reaction mixture was immersed in iee water for 5 hours, allowed to stand at room temperature for 4-8 hours and then distilled under reduced pressure through a 24 ineh fractionating oolumn packed with helices. . 0 25 distilled at 73.5-75.5 /lOmm, ~ aeetoxybutanol was 75%• 1.4235. 98.9 g. of liquid The yield of The material was completely Soluble in a small amount of water, showing that no diacetate was present since the diacetate is quite insoluble in water. An experiment was performed in which the acetylation was allowed to take place at temperatures between 50 and 70 degrees. An 89% yield (calculated as the acetoxybutanol) 0 25 was obtained of a liquid boiling at 78.5-80.0 /10 mm, N -o l.4189 . 25° d o 1.0144. This material was not completely soluble in -4 water. The physieal properties and the solubility indicate that this material aontains some diacetoxybutane. Apparently the aeetylation must be carries out at low temperatures in order to prevent formation of some diaeetate. - 10 - ~-2,3-Diaeetoxybutane. -- To 32 g. (0.36 mol) of 99.2% ~ ~lyeol (m.p. 33.6°) were added 80 g. (0.78 mol) of freshly distilled acetie anhydride and one drop -of sulfurie acid. The reaetion mixture was cooled under the tap, allowed to stand at room temperature for 12 hours and distilled under reduced pressure tl!frou~ a 24 inch fractionating column. The yield was ~7 ~• (75%) of liquid b.p. 76-76.5°/10 mm. Mixed melting point eurve of 2,3-diacetoxybutanes. -In order to provide a simple, accurate method of determining the composition of mixtures of meso and dl-2,3-diaeetoxybutane, a mixed meltin~ point curve was prepared. For the meltin~ point determinations on the mixtures, thin walled pyrex bulbs 10 mm in diameter with necks 2 mm in diameter were used. - - About 0.8 g. of mixtures of dl and meso-diaeetoxy• butane were wei~ed into the bulbs and the necks sealed. The bulbs were then suspended in a water bath which was me.e hani~ally stirred and equipped with a then:nometer graduated in tenths of degrees. By gently tapping the neck of the melting point bulb the contents could be violently agitated. The temperature was noted as the la-;s-t - crystals disappeared 0 while the bath temperature was being r~ised about o.2 ·/m1n. After the meltin~ points had been determined the refraqtive indices were taken on all of the mixtures which were liquid at 25°. A new Abbe ' refraotometer was used for these deter- minations. II and III. The results are presented in Table II and figures - 11 - Table II Melting points anq. r•e:fracti ve indices of mixt~res o f ~ and £!,-2,3-diacetoxybutane. meso -rT1{S m<5P • C 0 42.9 8.94 39 .1 18.20 35.7 30.48 29.7 40.9 24.2 1.4128 49.9 18.6 1.4126 61 . 5 10.7 1.4124 69.9 2.8 l .4123 87.2 o.a 1.4119 94.5 2.1 1.4118 100.0 3.0 1.4117 100.0 2 .5 1. 412111 1.412811 41.5 ~ - 2 . 3- Di -;e-Toluenesulf'onoxybutane. -- To 90 g . (l.O rnol) of meso-2.3-butanediol (m.p. 33.8 99.4% meoo) were added 400 g . (2.1 mol) of recrystallized 2-toiueneaulfonyl chloride and 174 g . (2.2 mol) of redistilled pyr1d.ine!t Tb.e 2-toluenesulfonyl chloride dissolved as the reaction mixture hea ted and after about 15 minutes a quantity of crystals of pyridine hydrochloride formed . The semi solid - 12 - mass was allowed to stand overnight and waa t1hen poured into eold d1lut.e hydroehlorie acid. solidified. An oil separated which soon It was washed several times with cold dilute hydrochlorio acid to remove the pyridine, then washed with water, filtered, dried and recrystallized from iso propyl ether. . . • g. Yi e ld : 212 .., 5 7..:,,'dkJ, m• p • 9~-94°. Repeated reeryotallizations • from anhydrous isop:rX)pyl ether gave a product melting at 95 .0-95~5°.• lrnal. Cale'd for C1aH220652 c, 54.25; H, 5.56; s , 16.09. I<'ound: A c, 54.60; H, 5.f54; s, 16 .09 .. sample of this compound was recrystallized twiee from methanol ~1v:tng a product meltine; 95-96°. This product apparently contained two molecules of alcohol of crystallization since saponificat1on.gave an eq uivalent wei gh t of 231; c a.i a'd erythro -2-Aeetoxy-3-.g-toluenesulfonoxybutane. -- 'i'o 45 g. (0.50 mol) or ~-2,3-butanediol (m.p. 34.0° 99.6% ' ~eso) were added 40 g. (0.51 rnol) of redistilled pyridine and 95.2 g. (0.50 mol) of E,-toluen esulfonyl e.hlo:r.ide. After a few minutes the mixture heated stronp;ly, was cooled under the tap, and after the r ea.o tl.on had subslded was allowed to at,s,nd at room temperature for 12 hours. Then 52 5• (0.5 mol) of freshly distilled aGetic anhydride and t hre e d rop s of sulfurt~ acid were added. th~ tap. Ag@.in the mi x ture wa,s cooled under After standing fot: three ho urs i t. was poured over a mixture of 42 g . (0.5 mol) of sodium bicarbonate and ice. - 13 - The product separated as a white eurd which was dissolved in ethyl eth.er, the ether solution washed several times w1 th water, dr1ed with calcium su1:t'at.e and cooled to o0 c. After stand1nt5 ten: 12 hours at o 0 c. a qua.nt1 ty of crystals had formed. The mother liquor was decanted and cooled to the temperature of solid carbon 'dioxide which cau s ed another crop of cryst.,a,ls to appear. The two crops of cry s tals were €:ombined givln(!; 87 g. (60% yi~td) of material,, m.p. 39-45°. • Several recrystallizations from anhydrous isopropyl ether gave a white crystalline product melting 51 .5-52 .o Ana.l . 0 . Calo•d for C13H1805S: G, 54.,53; : H,. 6.33. F'ound: c, 54.95; H, 6.33. - Aeetylation of the meso glycol to the 2-ae~toxy-3-buta.nol followed hy tosylati0n gave an i dentical product but the yields were much lower, around 25%• ~-di-2.,3-I?,-Bromobenzene sulfono xybutan e .. - - To 1.7 g. (0.019 mol) of ~-2.3-butaned1ol (m.p. 34° 99 -6% meso) were added 10 g. (0.039 mol) of p-bromo 1)E.mzenesul,fonyl chloride and 5 ml . of pyridine. 'the product was isola ted. i n the same manner as the tosy l a,tes and was recrysta.111 zed from absolute 0 ethanol, m.p. 123-124. Solvolysts Expertme n te 1. The anhydrous solvolysis of erythro-2-acetoxy-3-E- ·t olueneimlfonoxybutane. -- 35 g . of g lacial aaetic aCJid., 2 g. - J_.q. - of aoetie anhydride and 6.9 g. (0.07 mol) of potassium acetate (dried over P205) were plaeed. in a flask fitted with a reflux condenser having a drying tube at 1 t.a outlet. I t w~s bl"'..>u@5ht to a boil and by th.1s raeans all of the water was eliminated from the mixture. Then 10 g. (0.035 mol) of erythro-2-acetoxy- 3-2-toluenesulfonoxybutane were added and the mixture refluxed for two hours, allowed to st~nd for 48 hours at room temperature and poured over sodium bicarbonate and ice. The neutralized solution was extracted several times with e ·t her, the ether extraots combined and evaµorat,ed a11d the residue distilled under reduced pressure. The yield was 2.5 5• ( .l,-1%) of eolor- less liquid boiling at 75-76°/10 mm, m.p. 3°. ~~ 5 1.4117. - These constants indicate that the produet is pure mt-aio-2, 3diacetoxybutane. Some pure ~ - 2 , 3-diaeetoxybutane was put through exactly the same treatment and was recovered with no change in physical constants. 2. The anhydrous solvolys1s of £1!.!2.-2.3-di-.e.-toluene- aul:f'onoxybutane. -- 275 ml. of glacial acetic acid, 30 ml. of aoetlc anhyd.ride and 80 g. (0.8 mol) of potassium c1.cetate ( dried over P205 ) were put 1n a flask and orouf$ht to a boil,• - - Then 79.6 g,. (0.20 mol) of meso-2,3-c.1-p-tolueneaulfono~ybutane were a.dded. A reflu.x condenser was fitted to the flask and the mixture refluxed for 6 hours. Then t.he l1qu1d was put ina Cla1sen flask and as much liquid as poos1ble distilled rapidly at 40 mm pressure. When about half of the liquid was - 15 - removed the aontents of the flask solidified. The pressure was reduced to 2 mm and about 30 ml. mo re 11qu1d diet.ill ed. This dist.1llate was redlstilled throu.gh a fractiona ting column and gave 3.3 e;. of colorless liquid b.p. 60°/2 mm, which cry s tallized when seeded with a. s mall crystal of £!,- • diaeetoxybutane and melted at 32°. The solid material left in the Claisen fla sk was extracted with boilint15 1sopropyl ethe r and the extrac ts distilled through .a fractionatin~ column. 19.5 g. of colorl e ss liquid ca.rue over at 73.5 ...74.5°/10 mm. ~t'h is rua ter1.Ed crys tallized - when seeded w.1 th dl-cl1acetoxybutano a nd melted at 38-39°. Th e melting point of the first frac ~ion, 32° , indicates - a. com po s l tion of 711-% dl and the rnel tin~ point of the second • 0 - fraction ,. 39 • , 1nd1ca tes 88% dl or a. tot.al of 86% inversion • of t h e r eactio n o rod.ucts. '.l'his pereent~e of inversion was con firmed by a s eeond exper:tment, duplic e-.ting the one described. 3. Solvolysls of erythro-2-aeetoxy-3-E-toluenesulonoxy- butane' in the presence of water. -- 'fo 15 .g. (0.0525 mol) of eryth~-2-aaetoxy-3-~-toluenesulfonoxybutane were added 15 g. of potassium acetate (dried over P205), 40 g. of a cetic acid which contained 0.2 % water {m.p. 16.3°) and o.865 e;. of wa.ter, a total of 0.0525 mols of water. The mixture wa.s heated at 130-140° for 4 hours and left for 12 hours at room temperature. The product was isolated in the manner described for experiment 2 above. 'rhe yield was 5.4 g. of colorless liquid, b.p. 76- 78.5°/10 mm. ~ 5 1.4173• 'l'h1s refractive index 1ndieated that - 16 - the liquid was about 50% 2-acetoxy-3-butanol. so aoetic anhydri.de and a traoe o.f sulfuric aeid were added, the mixture allowed t.o stand for 12 hours and then d1st.,1lled through a 50 cm. spinning band eolumn. Th.e following three fractiona were collected: b.p./10 mm. m.p. weight. QC g. 1~ dl wt 5!1 e;. composition A 70-78.6 14 .27 43 -- 0.12 B 79-80 41.5 2.55 97 2.47 C 80 43 2-6!? 1(.:)0 - oc -- rfOTAL r:1 2.~ - - 5.24 5.4'7 This shows that 96% inversion took place. • Yleld of cU.acet.oxybuta.nea was 60%. 4. Solvolysi a of meeo -2, 3-di-E_-toluenesu.lfonoxybutane in the presence of water. -- ·ro 25 g. ( 0.063 mol) of meao-2.,3di-_2-toluenesulfonoxybutane were added 25 g. of potassium aeeta.te (dried over' r 2 o ), 50 g. of acetic. acid containln5 5 0.2 11 water (m.p. 16.3°) and 1.13 g. of water, a. total of 0.063 mols of' water. 'J:he mixture V'{ S. S 0 he&.ted to 130-l.L~o for 6 hours. kept at. room temperature for 12 hour·s am::: the product isolated by the procedure described for experiment 3 except, th.at acetie {mh.ydr1de was added before the mixture was disti lled. follovring three fractions were collectl;d: b.p.£10 mm C wt e;. A 69-r75 o.45 E 75-76 2.85 C 76-76-2 3.03 1.4117 T'he - 17 • The refract1.ve indices show this rr,aterial to be more than 90~; ~-2.3-diaoetoxybutane. Yield 58%. The 2,3-Di-d-eamphorsulfonoxybutanes., -- To 4.5 g. (0.05 mol) of pure £.!-2,3-butanedlol, obtained froni pure EY:, 2,,3diaeetoxybutane (m.p. 42.5°) )by' sa.poniti& ca.tion,, were added 20 ml. ot" pyr1cl1ne and 27.5 g. (0.11 mol) of freshly prepared ~-eamphoraulfonyl chloride. evolut.i on of heat. The reaction took plaee w1 th The mixture was kept at 500• for 3 h.ours, dissolved in 50 ml. of iaopropyl ether, and. water added. A white amorphous solid sepa.r a t.ed and ge. thered on tne eonta.iner walls and at the water-ether int.er-fe.ce.. rhe ath erial phase was separated emd a.fter a few hours deposited abOut 2 g rams of beautiful white crystals. Th e mother liquor was decanted, heated and. used t.o extrs,ct the ,,h:t te amorphous solid . After beine; kept at o0 ove .r n1ght some more of t,he crystals described above had been depos1 ted and also a number of hemispherical clumps of finely dlvided crystals. were separa..ted manually . The two types of crystals On recrystalli za.tion the first type had a me1 ting point of 105.5° and the second a melting point of 148-J.49°. In another e«:per1ment t.he reaction mixture was allowed to stand overnight an.d was poured into dilute HCl. An organic phase started. to separate and was taken up in 200 ml. of et,hyl ether and the ether ex·tract· dried and cooled to the temperature of solid carbon dioxide. A light feathery - 18 - crystalline sol1d came out. On subsequent recrystallization i t had a m.p. of 42-43°. The meiio-2. 3-d1-~-eamphoraulfonoxybu tane ,was prepared in the same way as the £l derivatives. It ha d a rneltine; point of 119.5-120.5°. Anal. ca1c •e for C24HJs¾ 0s J c,55.57; H, 7.38; Found: m.. p. 42° •• c. 54 .. 65; H, 7.46; ll ! •P• C' .• ,;;; 12.36. s, 1.2.55. 105°: c. ::.>t: ·6 ,. 12.. '• H, 7 .5-4; s. 12.65. w.p. ·1498 : c. 55 . 91; H, 7 .46; ·'• 12.45. m.p. 120°: c, 55.94; H, 7.65; s.. 12.73. 1-- - 19 - SWnmaz•.t 't he mechanism of the reaction in the subst1 tut1on of aeetoxy 5roups for .n-tolueneaulfonoxy groups in the 2, 3bu tanediol series has · been studied by means of the at.erie ehangeo in the products. The reactions were cc.rried out in a.eetie aaid solutions of potassium acetate,. both anhydrous and w:l th water present. Both with and without wa ter, the reactions goin~ from the 2.3-d1-_E-toluenesul:fonoxybutan~ to the 2-aoet,oxy-3-!,-toluenesulfonoxybutane were identical, but the eourse of t..½.e second aubst1 tution step was different in the two mediums. Under anhydrous cond.1 tions -there was 100% retention of configuration going from the acetoxy-_e-tolue.n esulfonoxybutane to the dia.oetoxy butane; but with one mol water present f'or each mol of ester,, there was 96% 1:nver·sion. 'l'he&e reactions o.re explained by the existence of a eyolic ortho-ester in·t ermediate. 'rhe di-g_-eai-nphorsulfons t e s of 2.J-butanediol were prepared as a etep 1n the possible resolution of the glycol. However. the conolualon of th1 s phase of the work waa prevented by the sudden oalline; of the author· in w the :cl li t a ry service. - 1. Hughe s~ 20 - l• Chem. soc., 255 (1935) f• Chem. ~3o c.::., 225 (1936) Hue-)les, Ingold, Shapiro, - - Hughes. Shapiro, J. Chem . Soc., 1177, 1192 ( 1937) Cooper, Hughes, --..- i• Cb.em. ~ • • 1183 (1937) Bateman, Hughes. l • Chem. ~ •, 1187 ( 193'7) 2. Cowdrey, Hughes, Ingold,. Masterman, Scott, !!,• Chem. So£•, 1252 ( 1937) 3. Winst.ein and Lucas, !!.• ~• Chem. So c., §! 2845 {1939) -~ et ante 4. __ - tucaa and Goulet.,_...,.. J Am . Chem . soc ., 63 2541 ( 1941) - W1nstein, Hess and Buckles, tT• Am . ,_,..__ Chem . ~ ,Soe .,- 64 ~ ~ 2796 (1942) 6. W1nste1n and Buck les, --~_......,,_--J. Aru. Chem. Soe ., ~ 61; 613 ( 1943) 7. Tipson-, a. Winatein and Buckles, J. Jun. Chem. ~(l•, 64 2780 ( 1942) i• fil:.21· Cbem., !.2Q. 55 ( 1939) Winstein and Buc kles, -i. - ~- - Chem. - soc., 2! 2787 ( 1942) 10. Wilson and Lucas, l• , Am. Ch.em. £--0 0., 2§. 2396 (1936) 11. W1nstein and Wood, l• ~ - Ch em. see., ~ 548 (1940) Fig. I o C. 50 40 r------~~ i"'-Q. ~ ............. 30 -------- "'- 20 ' ~ '1~ "" " I'-.. 10 "' "t , 0 1.---' l,.----4 .,. i--"' '\ 0 ,,. / -10 10 20 30 40 50 60 % meso form 7 0 80 90 Fig.II n25 D 1.4135 r-------_ ------r----....__ 1.4130 ~ 1.4125 ~ r----....._ ....... ~ 1.4120 r-------- ___ ()--. ~b 10 20 30 60 % meso form 40 50 Fig. Ill 70 80 90