Graduate Thesis Or Dissertation
 

Chiral synthesis of alcohols via asymmetric epoxidation

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/k0698b87r

Descriptions

Attribute NameValues
Creator
Abstract
  • Enantioselective epoxidation of crotyl alcohol, followed by a cuprate mediated methylation, gave a 1:1 mixture of (2S) -3- methyl -1,2- butanediol and (2R,3S)-2-methy1-1,3- butanediol. The latter was separated as its 2,4,6-trimethylbenzenesulfonate derivative and converted via the iodide to the corresponding phosphonium salt. The separated butanediol derivatives were independently transformed to (S)-3-methyl -2-butanol, thereby proving configuration and establishing optical purity. The primary trityl ether of the chiral butane-1,3- diol was converted to (2S,3R)-2-methy1-3-tert-butyldimethylsilyloxybutanal. The reaction of this aldehyde with methylmagnesium bromide and with methyllithium gave, after removal of the silyl group, meso and (2S,4S)-3-methy1-2,4- pentanediols. A study of this reaction at various temperatures led to the conclusion that stereoselectivity can be predicted by the Cram model when methyllithium is the reactant but not when the Grignard reagent is employed. In the latter case, a coordination model in which magnesium complexes in bidentate fashion to the carbonyl and 3-oxygen atoms successfully predicts the stereochemical outcome.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using Capture Perfect 3.0.82 on a Canon DR-9080C in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items