PART I: ALDOL REACTIONS OF 1,3-OXATHIOLAN-5-ONES. PART II: CAMPHOR AS A CHIRAL DIRECTING AGENT IN ALKYLATIONS OF GLYCINATES.
type: CreativeWork
description: Part I. 1,3-Oxathiolan-5-ones can be reduced to 2-mercaptoaldehydes which are synthetically important in the preparation of 2,5-dihydro-thiophenes and dienes.('1,2) Alkylation of 1,3-oxathiolan-5-ones was examined as a route to structurally more complex 2-mercaptoaldehydes. Alkylations were successful only with very reactive alkylating agents.('2,3) Aldol reactions were more successful. 1,3-Oxathiolan-5-ones were reduced with lithium aluminum hydride to 2-mercaptoalcohols, which could be transformed into the 2-(methylthio)alcohols. Part II. Camphor imines of glycinates were prepared from camphorthione and alkylated with various alkylating agents differing in steric requirements and reactivity. Diastereomeric excesses for alkylation with simple alkyl halides ranged from zero percent for methyl iodide to sixty percent for isobutyl iodide. Allylic alkylating agents showed much greater selectivity. Reactivity and steric requirements in the alkylating agent do not entirely explain the diastereoselectivity obtained in allylic cases, and a transition state interaction between the II-systems of the alkylating agent and the enolate has been postulated to explain enhanced stereoselectivity. Reduction of the alkylated camphor iminoesters gave iminoalcohols with no loss of stereochemical integrity. Transamination of the camphor imines to amino esters and amino alcohols can be achieved with hydroxylamine acetate.Dept. of Chemistry and Biochemistry. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1985 .M574. Source: Dissertation Abstracts International, Volume: 46-09, Section: B, page: 3057. Thesis (Ph.D.)--University of Windsor (Canada), 1985.
abstract: Part I. 1,3-Oxathiolan-5-ones can be reduced to 2-mercaptoaldehydes which are synthetically important in the preparation of 2,5-dihydro-thiophenes and dienes.('1,2) Alkylation of 1,3-oxathiolan-5-ones was examined as a route to structurally more complex 2-mercaptoaldehydes. Alkylations were successful only with very reactive alkylating agents.('2,3) Aldol reactions were more successful. 1,3-Oxathiolan-5-ones were reduced with lithium aluminum hydride to 2-mercaptoalcohols, which could be transformed into the 2-(methylthio)alcohols. Part II. Camphor imines of glycinates were prepared from camphorthione and alkylated with various alkylating agents differing in steric requirements and reactivity. Diastereomeric excesses for alkylation with simple alkyl halides ranged from zero percent for methyl iodide to sixty percent for isobutyl iodide. Allylic alkylating agents showed much greater selectivity. Reactivity and steric requirements in the alkylating agent do not entirely explain the diastereoselectivity obtained in allylic cases, and a transition state interaction between the II-systems of the alkylating agent and the enolate has been postulated to explain enhanced stereoselectivity. Reduction of the alkylated camphor iminoesters gave iminoalcohols with no loss of stereochemical integrity. Transamination of the camphor imines to amino esters and amino alcohols can be achieved with hydroxylamine acetate.Dept. of Chemistry and Biochemistry. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1985 .M574. Source: Dissertation Abstracts International, Volume: 46-09, Section: B, page: 3057. Thesis (Ph.D.)--University of Windsor (Canada), 1985.
author: MISHRA, PRATIBHA.
language: en_CA
license: http://creativecommons.org/licenses/by-nc-nd/4.0/
date published: 1985-01-01
date modified: 2026-07-27T22:04:49Z
provider: University of Windsor
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Windsor

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property ID: Handle
value: https://hdl.handle.net/20.500.14776/2649