STEREOCHEMICAL STUDIES ON HEMIORTHOTHIOL AND HEMIORTHOTHIOLATE TETRAHEDRAL INTERMEDIATES
Abstract
A study of hemiorthothiol tetrahedral intermediates R(,1)C(OR(,2))(,2) (SH) {45} was undertaken to uncover the role of stereoelectronic control in the breakdown of {45} which was generated by the ion-ion combination of NaSH('-) and dialkoxycarbonium cations R(,1)C('+)(OR(,2))(,2)BF(,4)('-). In the breakdown of 2-mercapto intermediates {46} and {48} derived from 1,3-dioxolan-2-ylium, 1,3-dioxan-2-ylium and 1,3-dioxa-2-decalyl fluoroborate salts, both C-O bonds were found to cleave under similar stereo-electronic effects, whereas lack of proper orbital orientation in trans-9-mercapto-1,8-dioxadecalin {49} prevented its breakdown. The breakdown of tetrahedral intermediates {51} and {52} obtained from bicyclic O-ethyl-(delta)-valerolactonium salts proved to be in agreement with the stereoelectronic theory. Under kinetic conditions preferential cleavage of the endocyclic C-O bond in each of {51} and {52} was observed. The breakdown of tetrahedral intermediates from acyclic and cyclic dialkoxycarbonium ions and NaSH or Na(,2)S provided a new synthesis of thionoesters. A novel class of stable, isolable anionic hemiorthothiolate tetrahedral intermediates is reported. The sulfhydrolysis of O-alkyl lactonium salts was found to provide a novel synthetic route to five-, six- and seven-membered thionolactones.
Subject Area
Organic chemistry
Recommended Citation
KHOURI, FARID FOUAD, "STEREOCHEMICAL STUDIES ON HEMIORTHOTHIOL AND HEMIORTHOTHIOLATE TETRAHEDRAL INTERMEDIATES" (1981). ETD Collection for Fordham University. AAI8111547.
https://research.library.fordham.edu/dissertations/AAI8111547
