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Sulfonation of alkenes with sulfur trioxide; stereospecific β-sultone formation
Tetrahedron Letters,Vol.28,No.l5,pp 1699-1702,1987 Printed in Great Britain
0040-4039/87 $3.00 + .OO Pergamon Journals Ltd.
SULFONATION OF ALKENESWITH SULFURTRIOXIDE; STEREOSPECIFIC &SULTONE FORMATION' Bert H. Bakkerand Hans Cerfontain* Laboratoryfor OrganicChemistry,Universityof Amsterdam, NieuweAchtergracht 129, 1018WS Amsterdam,The Netherlands. and (Z)- and (El-4-octene with Abstract:Sulfonation of I-octene,(E)-I-deuterio-1-octene, one mol-equivof sulfurtrToxideyieldsthe B-sultones Ta-d respectively. The reactionproceedsstereospecifically via a concerted-ci&&addition. In relationto our studieson the sulfonation of aromaticcompounds2we have now also taken an activeinterestin reactionsof alkeneswith sulfurtrioxide.The sulfonation of olefins 3 The sulfonation with sulfurtrioxidehas been known for more than a century. of long chain u-olefinshas gaineda lot of attentionin particularsince thesereactionsare 4 appliedcommercially for the preparation of surfactants.The reactionof alkeneswith neat sulfurtrioxideis extremelyvigorous.After the discoveryof the moderatingeffectof dioxane5 and pyridine6on the reactivityof sulfurtrioxidesystematicinvestigations to elucidate 7-9 It was proposedthat B-sultonesor the reactionmechanismwere carriedout by Bordwell. 11 10 are the initialproductsof the reactionof SO with alkenes. zwitterionic intermediates 3 Via a numberof subsequentreactionsthe labileintermediates give rise to complexmixtures 12 In order to gain information of alkenesulfonic acids and y- and 6-sultones. on the mechanism of the primarystep in the sulfonation of olefinsa carefulexamination of the initial productswith NMR spectroscopy at low temperatures was undertaken. 16 13-15and trappingexperiments There is evidencefrom spectroscopic studies that the SO3 sulfonation of alkenesleads initiallyto B-sultonesas major products.However,undermost reactionconditionsthese B-sultonesare unstableshort-lived species.Mori was able to 13 and in the case of fluoro-olefins isolatea solid B-sultonederivedfrom l-dodecene the 17 relativelystableB-sultonescan often be obtainedas such. 16 For the formationof fl-sultones two possiblemechanismsmay be considered. For simplealkenes
+ l-4
-
products
b
\ p- sultone
i-t Q-SO2
1699
1700
17. and fluoro-olefins, It 1s generallyassumedthat the firststep is electrophilic attack of sulfurtrioxideon the doublebond. In agreementwith Markovnikov's rule a zwitterionic intermediate"is formedwhich undergoesreversiblecyclization to form the B-sultone (mechanism a). As an alternative(mechanism b) the R-sultoneis formeddirectlyby a concertedcycloaddition.18 Evidencein favorof the concertedmechanismis the observedstereo13,14 specificity in the sulfonation of the (E)and (Z)-isomers of internalolefins. RecentlyRobertsproposedthat the small differences in the ratesof sulfonation of a number of relatedalkenesare best exolainedin termsof the thermallyallowedCn2s + n2sl cyclo-
We have studiedthe sulfonation of a medium-sized terminalolefin 1-octeneand the internal olefins(E)and (Z)-4-octene with both sulfurtrioxideassociated with dioxaneand with free sulfurtrioxide.The unstableprimarysulfonation productswere monitoredat low temperatures with 'H NMR.19 Reactionof I-octenela with one mol-equiv of sulfurtrioxidecomplexedwith = q
Table 1. ’ H NMR dataa of the B-sultones2 obtainedfrom the alkenes!I<. 1
R4 d
x
R’ So,
o,s/o-ti 4 I?=
d
R3
2.10
m
CH
a Chemicalshiftswere measuredrelativeto virtualinternalTMS. The underlineddata are the couplingconstantsin Hz. b The data may be reversed.
1701
(*H8)dioxane in C2H2C12 at -20°C gave the corresponding I,*-sultone2~ as demonstrated by its characteristic 'H NMR signals at 6 4.21 (dd, J=5.3, 12.2 HZ), 4.66 (dd, J-7.5, 12.2 Hz), and 4.55 (m) ppm (see Table 1). The absorption at 6 4.21 ppm is assigned to the hydrogen -cis to the n-hexyl group due to shielding by that moiety. A similar NMR pattern was reported for the 1,2-sultonederived from 1-dodecene.13b,20 In order to investigate the stereospecificityof the 1,2-sultoneformation we used (E)-1-(2H)21 -1-octene (Ai) as substrate. Its sulfonationwith one mol-equiv of S03-dioxane afforded only the trans-1,2-s&tone gk with specific NMR signals at
6
4.20 (d, J=5.8 Hz) and 4.55
(pseudo quartet) ppm. Obviously a regio- and stereospecificcycloadditionhas occurred in accordance with concerted mechanism b. It has been suggested that dioxane plays an essential role in the mechanism of the sulfonation with sulfur trioxide by stabilizing the zwitterionic 7 However, sulfonation of the deuterio-I-octenelk with free sulfur trioxide intermediate. without dioxane afforded exclusively the same stereospecifictrans-1,2-sultoneii- Apparently, the complexing agent dioxane only moderates the reactivity of sulfur trioxide, but does not alter the stereospecificityof the reaction. 16 Solutions of the unstable trans-1,2-sultone2; in C2H2C12 were found to be rearranged after 24 h at room temperature for about 85% to yield a mixture of 2-octene-I-sulfonicacid and the y- and 6-sultones. We did not observe any -trans-cis isomerizationof the residual 1,2-sultone z!, thus excluding a fast equilibrium between the 1,2-sultoneand the zwitterion. Sulfonation of the internal olefin (Z)-4-octene (A$) with one mol-equiv of sulfur trioxide complexed with dioxane in C2H2C12 at -20°C afforded e-6-sultone specific NMR signals at
6
22, as demonstrated by the
4.57 (dt, J=9.4, 2.4 Hz) and 4.78 (m) ppm. Similarly reaction of
the isomeric (E)-4-octene (ii) with S03-dioxane gave the correspondingtrans-t3-sultone 24 with as typical NMR absorptions two pseudo quartets at 6 4.15 and 4.32 ppm. The assignments of the NMR absorptions for these internal B-sultones (see Table I) are based on reported values for the sulfonation products obtained from the two isomeric 2-butenes.13 The internal B-sultones 2s and 2: are both thermally more stable than the terminal 1,2-sultone2~. After 24 h at room temperature still 9C% of these internal B-sultones are present in solution. There is no -cis-trans isomerizationof these B-sultones in solution at room temperature. Accordingly, it is concluded that the sulfonations of terminal as well as internal olefins with sulfur trioxide are concerted cycloadditionreactions and that the resulting B-sultones are not in equilibrium with the ring-opened dipolar structures. The further reaction of the B-sultones with sulfur trioxide will be the subject of a forthcoming communication. ACKNOWLEDGEMENTS:We wish to thank Dr. A.D. Vreugdenhil and Dr. T.A.B.M. Bolsman for many stimulating and helpful discussions and Mmes N.E. Bruinzeel and H. van der Laan-Ctvrteckova for skilfully measuring the NMR spectra. The financial support by Shell Research B.V. is gratefully acknowledged.
1702
REFERENCES AND NOTES: 1. Aliphatic sulfonation. Part 1. 2. H. Cerfontain, Recl.Trav.Chim.Pays-Bas 104, 153 (1985). 3. V. Regnault, Ann. 2,
32 (1837).
4. Surfactant Science Series, Vol. 7, "Anionic Surfactants",Ed. W.M. Linfield, M. Dekker, Inc., New York, 1976, Part I, B.E. Edwards, Chapter 4, p. 111; Part II, H.A. Green, Chapter 10, p. 345. 5. C.M. Suter, P.B. Evans, and J.M. Kiefer, J.Am.Chem.Soc.60_,538 (1938). 6. A.P. Terent'ev and A.V. Dombrovskii, J.Gen.Chem. USSR 2,
1467 (1949).
7. F.G. Bordwell and M.L. Peterson, J.Am.Chem.Soc.7&, 3952, 3957 (1954). 8. F.G. Bordwell and C.S. Rondestvedt, J.Am.Chem.Soc.70, 2429 (1948). 9. F.G. Bordwell and C.E. Osborne, J.Am.Chem.Soc.81, 1995 (1959). 10. J.K. Weil, A.J. Stirton, and F.D. Smith, J-Am. Oil Chem.Soc. G
873 (1965); F. Piischel,
Tenside 4, 320 (1967); H. Baumann, W. Stein, and M. Voss, Fette, Seifen, Anstrichmittel 72, 247 (1970). 11. E.E. Gilbert,"Sulfonationand Related Reactions",IntersciencePublishers, New York, N.Y., 1965. 12. J.L. Boyer, J.P. Canselier,andV. Castro, J.Am. Oil Chem.Soc. 2,
458 (1982).
13. a) M. Nagayama, 0. Okumura, S. Noda, and A. Mori, J.Chem.Soc., Chem.Connnun.1973, 841; M. Nagayama, 0. Okumura, S. Noda, H. Mandai, and A. Mori, Bull.Chem.Soc.Japan 3,
2158
(1974); k) A. Mori and M. Nagayama, Tenside lo, 64 (1973). 14. W.A. Thaler and C. DuBrueil, J.Polym.Sci.,Polym.Chem.Ed.22, 3905 (1984). 15. J.L. Boyer, J.P. Canselier, and V. Castro, XVI Jornadas de1 Comit6 de la Detergencia, AID, Barcelona, 1985, p. 247. 16. J.L. Boyer, B. Gilot, and J.P. Canselier, Phosphorus and Sulfur 20, 259 (1984). 17. 1-L. Knunyants and G.A. Sokolski, Angew.Chem.11, 623 (1972). 18. D.W. Roberts, D.L. Williams, and D.Bethel, J.Chem.Soc. Perkin Trans. II 1985, 389. 19. As a typical example the sulfonation of 1-octene was performed as follows: Liquid sulfur trioxide (10 &,0.24 rmnol)was injected into a stirred solution of 30 UL of (2H8)dioxane (0.32 mmol) in 0.5 mL of C2H2C12, cooled at -3OOC under an Ar atmosphere. Then 35 PL of I-octene (0.22 mmol) was injected into the stirred solution. The reaction mixture was transferredunder Ar into a cooled NMR tube and 'H NMR spectra were taken regularly at temperatures ranging from -20°C up to room temperature on a Bruker WM 250 apparatus. 20. A. Mori, M. Nagayama, M. Aoki, and K. Yaguchi, Kogyo Kagaku Zasshi -74, 706 (1971); through Chem.Abstr.75, 48364x (1971). 21. (E)_l_(2H)_l-octenewas prepared from I-octyne as described for the corresponding I-decene; D.W. Patrick, L.K. Truesdale, S.A. Biller, and K.B. Sharpless, J.Org.Chem.2, 2628 (1978). (Received
in UK 11 February
1987)
0040-4039/87 $3.00 + .OO Pergamon Journals Ltd.
SULFONATION OF ALKENESWITH SULFURTRIOXIDE; STEREOSPECIFIC &SULTONE FORMATION' Bert H. Bakkerand Hans Cerfontain* Laboratoryfor OrganicChemistry,Universityof Amsterdam, NieuweAchtergracht 129, 1018WS Amsterdam,The Netherlands. and (Z)- and (El-4-octene with Abstract:Sulfonation of I-octene,(E)-I-deuterio-1-octene, one mol-equivof sulfurtrToxideyieldsthe B-sultones Ta-d respectively. The reactionproceedsstereospecifically via a concerted-ci&&addition. In relationto our studieson the sulfonation of aromaticcompounds2we have now also taken an activeinterestin reactionsof alkeneswith sulfurtrioxide.The sulfonation of olefins 3 The sulfonation with sulfurtrioxidehas been known for more than a century. of long chain u-olefinshas gaineda lot of attentionin particularsince thesereactionsare 4 appliedcommercially for the preparation of surfactants.The reactionof alkeneswith neat sulfurtrioxideis extremelyvigorous.After the discoveryof the moderatingeffectof dioxane5 and pyridine6on the reactivityof sulfurtrioxidesystematicinvestigations to elucidate 7-9 It was proposedthat B-sultonesor the reactionmechanismwere carriedout by Bordwell. 11 10 are the initialproductsof the reactionof SO with alkenes. zwitterionic intermediates 3 Via a numberof subsequentreactionsthe labileintermediates give rise to complexmixtures 12 In order to gain information of alkenesulfonic acids and y- and 6-sultones. on the mechanism of the primarystep in the sulfonation of olefinsa carefulexamination of the initial productswith NMR spectroscopy at low temperatures was undertaken. 16 13-15and trappingexperiments There is evidencefrom spectroscopic studies that the SO3 sulfonation of alkenesleads initiallyto B-sultonesas major products.However,undermost reactionconditionsthese B-sultonesare unstableshort-lived species.Mori was able to 13 and in the case of fluoro-olefins isolatea solid B-sultonederivedfrom l-dodecene the 17 relativelystableB-sultonescan often be obtainedas such. 16 For the formationof fl-sultones two possiblemechanismsmay be considered. For simplealkenes
+ l-4
-
products
b
\ p- sultone
i-t Q-SO2
1699
1700
17. and fluoro-olefins, It 1s generallyassumedthat the firststep is electrophilic attack of sulfurtrioxideon the doublebond. In agreementwith Markovnikov's rule a zwitterionic intermediate"is formedwhich undergoesreversiblecyclization to form the B-sultone (mechanism a). As an alternative(mechanism b) the R-sultoneis formeddirectlyby a concertedcycloaddition.18 Evidencein favorof the concertedmechanismis the observedstereo13,14 specificity in the sulfonation of the (E)and (Z)-isomers of internalolefins. RecentlyRobertsproposedthat the small differences in the ratesof sulfonation of a number of relatedalkenesare best exolainedin termsof the thermallyallowedCn2s + n2sl cyclo-
We have studiedthe sulfonation of a medium-sized terminalolefin 1-octeneand the internal olefins(E)and (Z)-4-octene with both sulfurtrioxideassociated with dioxaneand with free sulfurtrioxide.The unstableprimarysulfonation productswere monitoredat low temperatures with 'H NMR.19 Reactionof I-octenela with one mol-equiv of sulfurtrioxidecomplexedwith = q
Table 1. ’ H NMR dataa of the B-sultones2 obtainedfrom the alkenes!I<. 1
R4 d
x
R’ So,
o,s/o-ti 4 I?=
d
R3
2.10
m
CH
a Chemicalshiftswere measuredrelativeto virtualinternalTMS. The underlineddata are the couplingconstantsin Hz. b The data may be reversed.
1701
(*H8)dioxane in C2H2C12 at -20°C gave the corresponding I,*-sultone2~ as demonstrated by its characteristic 'H NMR signals at 6 4.21 (dd, J=5.3, 12.2 HZ), 4.66 (dd, J-7.5, 12.2 Hz), and 4.55 (m) ppm (see Table 1). The absorption at 6 4.21 ppm is assigned to the hydrogen -cis to the n-hexyl group due to shielding by that moiety. A similar NMR pattern was reported for the 1,2-sultonederived from 1-dodecene.13b,20 In order to investigate the stereospecificityof the 1,2-sultoneformation we used (E)-1-(2H)21 -1-octene (Ai) as substrate. Its sulfonationwith one mol-equiv of S03-dioxane afforded only the trans-1,2-s&tone gk with specific NMR signals at
6
4.20 (d, J=5.8 Hz) and 4.55
(pseudo quartet) ppm. Obviously a regio- and stereospecificcycloadditionhas occurred in accordance with concerted mechanism b. It has been suggested that dioxane plays an essential role in the mechanism of the sulfonation with sulfur trioxide by stabilizing the zwitterionic 7 However, sulfonation of the deuterio-I-octenelk with free sulfur trioxide intermediate. without dioxane afforded exclusively the same stereospecifictrans-1,2-sultoneii- Apparently, the complexing agent dioxane only moderates the reactivity of sulfur trioxide, but does not alter the stereospecificityof the reaction. 16 Solutions of the unstable trans-1,2-sultone2; in C2H2C12 were found to be rearranged after 24 h at room temperature for about 85% to yield a mixture of 2-octene-I-sulfonicacid and the y- and 6-sultones. We did not observe any -trans-cis isomerizationof the residual 1,2-sultone z!, thus excluding a fast equilibrium between the 1,2-sultoneand the zwitterion. Sulfonation of the internal olefin (Z)-4-octene (A$) with one mol-equiv of sulfur trioxide complexed with dioxane in C2H2C12 at -20°C afforded e-6-sultone specific NMR signals at
6
22, as demonstrated by the
4.57 (dt, J=9.4, 2.4 Hz) and 4.78 (m) ppm. Similarly reaction of
the isomeric (E)-4-octene (ii) with S03-dioxane gave the correspondingtrans-t3-sultone 24 with as typical NMR absorptions two pseudo quartets at 6 4.15 and 4.32 ppm. The assignments of the NMR absorptions for these internal B-sultones (see Table I) are based on reported values for the sulfonation products obtained from the two isomeric 2-butenes.13 The internal B-sultones 2s and 2: are both thermally more stable than the terminal 1,2-sultone2~. After 24 h at room temperature still 9C% of these internal B-sultones are present in solution. There is no -cis-trans isomerizationof these B-sultones in solution at room temperature. Accordingly, it is concluded that the sulfonations of terminal as well as internal olefins with sulfur trioxide are concerted cycloadditionreactions and that the resulting B-sultones are not in equilibrium with the ring-opened dipolar structures. The further reaction of the B-sultones with sulfur trioxide will be the subject of a forthcoming communication. ACKNOWLEDGEMENTS:We wish to thank Dr. A.D. Vreugdenhil and Dr. T.A.B.M. Bolsman for many stimulating and helpful discussions and Mmes N.E. Bruinzeel and H. van der Laan-Ctvrteckova for skilfully measuring the NMR spectra. The financial support by Shell Research B.V. is gratefully acknowledged.
1702
REFERENCES AND NOTES: 1. Aliphatic sulfonation. Part 1. 2. H. Cerfontain, Recl.Trav.Chim.Pays-Bas 104, 153 (1985). 3. V. Regnault, Ann. 2,
32 (1837).
4. Surfactant Science Series, Vol. 7, "Anionic Surfactants",Ed. W.M. Linfield, M. Dekker, Inc., New York, 1976, Part I, B.E. Edwards, Chapter 4, p. 111; Part II, H.A. Green, Chapter 10, p. 345. 5. C.M. Suter, P.B. Evans, and J.M. Kiefer, J.Am.Chem.Soc.60_,538 (1938). 6. A.P. Terent'ev and A.V. Dombrovskii, J.Gen.Chem. USSR 2,
1467 (1949).
7. F.G. Bordwell and M.L. Peterson, J.Am.Chem.Soc.7&, 3952, 3957 (1954). 8. F.G. Bordwell and C.S. Rondestvedt, J.Am.Chem.Soc.70, 2429 (1948). 9. F.G. Bordwell and C.E. Osborne, J.Am.Chem.Soc.81, 1995 (1959). 10. J.K. Weil, A.J. Stirton, and F.D. Smith, J-Am. Oil Chem.Soc. G
873 (1965); F. Piischel,
Tenside 4, 320 (1967); H. Baumann, W. Stein, and M. Voss, Fette, Seifen, Anstrichmittel 72, 247 (1970). 11. E.E. Gilbert,"Sulfonationand Related Reactions",IntersciencePublishers, New York, N.Y., 1965. 12. J.L. Boyer, J.P. Canselier,andV. Castro, J.Am. Oil Chem.Soc. 2,
458 (1982).
13. a) M. Nagayama, 0. Okumura, S. Noda, and A. Mori, J.Chem.Soc., Chem.Connnun.1973, 841; M. Nagayama, 0. Okumura, S. Noda, H. Mandai, and A. Mori, Bull.Chem.Soc.Japan 3,
2158
(1974); k) A. Mori and M. Nagayama, Tenside lo, 64 (1973). 14. W.A. Thaler and C. DuBrueil, J.Polym.Sci.,Polym.Chem.Ed.22, 3905 (1984). 15. J.L. Boyer, J.P. Canselier, and V. Castro, XVI Jornadas de1 Comit6 de la Detergencia, AID, Barcelona, 1985, p. 247. 16. J.L. Boyer, B. Gilot, and J.P. Canselier, Phosphorus and Sulfur 20, 259 (1984). 17. 1-L. Knunyants and G.A. Sokolski, Angew.Chem.11, 623 (1972). 18. D.W. Roberts, D.L. Williams, and D.Bethel, J.Chem.Soc. Perkin Trans. II 1985, 389. 19. As a typical example the sulfonation of 1-octene was performed as follows: Liquid sulfur trioxide (10 &,0.24 rmnol)was injected into a stirred solution of 30 UL of (2H8)dioxane (0.32 mmol) in 0.5 mL of C2H2C12, cooled at -3OOC under an Ar atmosphere. Then 35 PL of I-octene (0.22 mmol) was injected into the stirred solution. The reaction mixture was transferredunder Ar into a cooled NMR tube and 'H NMR spectra were taken regularly at temperatures ranging from -20°C up to room temperature on a Bruker WM 250 apparatus. 20. A. Mori, M. Nagayama, M. Aoki, and K. Yaguchi, Kogyo Kagaku Zasshi -74, 706 (1971); through Chem.Abstr.75, 48364x (1971). 21. (E)_l_(2H)_l-octenewas prepared from I-octyne as described for the corresponding I-decene; D.W. Patrick, L.K. Truesdale, S.A. Biller, and K.B. Sharpless, J.Org.Chem.2, 2628 (1978). (Received
in UK 11 February
1987)