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Silyl enol ethers as new protecting groups for alkyl 4-halo-3-oxobutanoates; The preparation of pure (3-alkoxycarbonyl-2-oxopropyl)triphenylphosphonium salts

Citation

Moorhoff, CM, Silyl enol ethers as new protecting groups for alkyl 4-halo-3-oxobutanoates; The preparation of pure (3-alkoxycarbonyl-2-oxopropyl)triphenylphosphonium salts, Journal of the Chemical Society-Perkin Transactions, 1, (13) pp. 1987-1995. ISSN 0300-922X (1997) [Refereed Article]

DOI: doi:10.1039/a700241f

Abstract

A new method has been developed for the preparation of pure (3-alkoxycarbonyl-2-oxopropyl)triphenyl-phosphonium salts 8. Alkyl 4-bromo-3-oxobutanoates and alkyl 4-chloro-3-oxobutanoates 7 are protected as the trimethylsilyl enol ethers prior to treatment of the resulting bromo(trimethylsilyl enol ether) esters 20c and 21c with triphenylphosphine in toluene and then addition of a little water to give pure (3-isopropoxycarbonyl-2-oxopropyl)triphenylphosphonium bromide 8c. Bromo(silyl enol ether) esters react more efficiently with triphenylphosphine than the chloro(silyl enol ether) esters. tert-Butyldimethylsilyl enol ethers of alkyl 4-bromo-3-oxobutanoates and alkyl 4-chloro-3-oxobutanoates 7 also react with triphenylphosphine. Protection of isopropyl 4-bromo-3-oxobutanoate 7c as the enol acetate followed by subsequent reaction with triphenylphosphine gives (Z)-(2-acetoxy-3-isopropoxycarbonylbut-2-enyl)triphenylphosphonium bromide 17.

Item Details

Item Type:Refereed Article
Research Division:Chemical Sciences
Research Group:Organic chemistry
Research Field:Organic chemical synthesis
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the chemical sciences
UTAS Author:Moorhoff, CM (Dr Moorhoff)
ID Code:12012
Year Published:1997
Web of Science® Times Cited:8
Deposited By:Chemistry
Deposited On:1997-08-01
Last Modified:2011-08-15
Downloads:0

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