Mechanistic And Synthetic Aspects Of The Sulfonyl Group

This thesis describes the results from two different projects in organosulfur chemistry, the first part dealing with the reactions of arylsulfenes with sulfur dioxide, and the second part with the chemistry of {lcub}2{rcub}betylates.;Phenylsulfene and diphenylsulfene, obtained by the reaction of 2,6-lutidine with appropriate precursors, react with sulfur dioxide to give, respectively, benzaldehyde and benzophenone, in confirmation of the suggestion of Staudinger and Pfenninger that the benzophenone formed in the reaction of diphenyldiazomethane with sulfur dioxide arises from reaction of the latter with sulfene. (\u2718)O-Labelling experiments in the reaction of diphenylsulfene with sulfur dioxide indicate that the oxygen atoms in about two-thirds of the benzophenone molecules come from the sulfur dioxide, whereas diphenylsulfene itself supplies the oxygen atoms for the remaining third. Previously suggested mechanisms predict that the benzophenone oxygens come only from the sulfur dioxide. General processes that could lead to the observed labelling pattern are discussed and specific examples presented. The available evidence is not sufficient to establish a single mechanism for the reaction of arylsulfenes with sulfur dioxide.;2-Alkoxysulfonyl trialkylethanaminium salts ( {lcub}2{rcub}betylates ) were used as intermediates in converting primary and secondary alcohols to a wide variety of substitution products. The procedures are characterized by mild conditions, easy workup, generally good yields and clean products. Using {lcub}2{rcub}betylates as intermediates, alcohols were converted to alkanesulfonyl chlorides, alkyl halides, alkyl esters of sulfonic acids, alkyl acetates and numerous other products. On treatment with basic nucleophiles {lcub}2{rcub}betylates undergo Hofmann elimination to give ethenesulfonate esters. {lcub}2{rcub}Betylates were also used for the synthesis of alkyl esters of hydroxyalkanesulfonic acids, a little-known class of compounds. Chiral secondary alcohols gave substitution products, in most of the cases, with complete inversion of configuration and hence, proving the involvement of an S(,N)2 process in these reactions