Predominant Intramolecular Pummerer Reactions of Substituted Benzyl p-Tolyl Sulfoxides with Acetic Anhydride
- 1 January 1983
- journal article
- Published by Oxford University Press (OUP) in Bulletin of the Chemical Society of Japan
- Vol. 56 (1) , 266-269
- https://doi.org/10.1246/bcsj.56.266
Abstract
In the Pummerer reactions of 18O-labeled benzyl, and 3,5-dichlorobenzyl p-tolyl sulfoxides with a large excess of unlabeled acetic anhydride in the presence of DCC as acid scavenger, the resulted Pummerer reaction products, the α-acetoxy sulfides, were found to have retained substantial amounts of 18O-label of the original sulfoxides, i.e., nearly a half or more. Meanwhile, when optically active benzyl, 3-chlorobenzyl, and 3,5-dichlorobenzyl p-tolyl sulfoxides were allowed to react with excess acetic anhydride in the presence of DCC, the α-acetoxy sulfides, the Pummerer reaction products obtained, were found to have no optical activity. These observations suggest that the acetoxyl migration from sulfur atom to α-carbon is predominantly intramolecular, however, the α-(p-tolylthio) carbenium acetate ion-pair formed during the reaction prior to racemization is less intimate than those which are formed in the reactions of cyanomethyl and (α-carbonyl-substituted methyl) p-tolyl sulfoxides which give the corresponding highly optically active α-acetoxy sulfides.This publication has 15 references indexed in Scilit:
- Intermolecular Stereoselective Pummerer Reactions of 4-(p-Chlorophenyl)thiane 1-Oxides and trans-1-Thiadecalin 1-Oxides and 2-Thiadecalin 2-Oxides with Acetic AnhydrideBulletin of the Chemical Society of Japan, 1983
- Intramolecular Stereospecific Pummerer Reactions of Aryl (Substitutedmethyl) Sulfoxides Bearing Electron-withdrawing Groups with Acetic AnhydrideBulletin of the Chemical Society of Japan, 1983
- Substitution at a saturated carbon atom. XVII. Organic ion pairs as intermediates in nucleophilic substitution and elimination reactionsAccounts of Chemical Research, 1973
- Reaction of Sulfoxides with Acylating Reagents. II. Mechanism of the Reactions of Aryl Benzyl Sulf oxides with Acetic AnhydrideBulletin of the Chemical Society of Japan, 1970
- Substitution at a saturated carbon atom. XII. Generality of the ion-pair mechanism of nucleophilic substitutionJournal of the American Chemical Society, 1969
- Substitution at a saturated carbon atom. X. Unification of mechanisms Snl and Sn2Journal of the American Chemical Society, 1969
- Oxygen-18 scrambling in solvolyses of simple unactivated alkyl arenesulfonatesJournal of the American Chemical Society, 1968
- Substitution at a Saturated Carbon Atom. IV. A Clarification of the Mechanism of Solvolyses of 2-Octyl Sulfonates. Stereochemical Considerations1Journal of the American Chemical Society, 1965
- Model pathways for enzymatic oxidate demethylation—ITetrahedron, 1963
- XLV.—Benzyl sulphoxide: a possible example of dynamic isomerismJournal of the Chemical Society, Transactions, 1909