Synthesis of α-hydroxy-β,β-difluoro-γ-ketoesters via [3,3]sigmatropic rearrangements

Michael Broadhurst; Samantha J  Brown; Jonathan Percy; Michael E  Prime

doi:10.1039/B004766J

Synthesis of α-hydroxy-β,β-difluoro-γ-ketoesters via [3,3]sigmatropic rearrangements

Michael Broadhurst, Samantha J Brown, Jonathan Percy, Michael E Prime

Pure And Applied Chemistry

Research output: Contribution to journal › Article

28 Citations (Scopus)

37 Downloads (Pure)

Abstract

Readily available γ,γ-difluorinated allylic alcohols obtained from trifluoroethanol were esterified efficiently. Exposure to strong base (LDA) afforded the ester enolates, in which chelation both controlled configuration and stabilised against fragmentation, which were trapped as their silyl ketene acetals. Rearrangement occurred to afford base-sensitive acid products. Esterification under mild conditions afforded the purifiable methyl esters in which the masked ketone had been released. Educts with either a benzyloxy or an allyloxy group at the α-position could be deprotected releasing the alcohols.

Original language	English
Pages (from-to)	3217-3226
Number of pages	10
Journal	Journal of the Chemical Society, Perkin Transactions 1
Volume	2000
Issue number	19
Early online date	11 Sep 2000
DOIs	https://doi.org/10.1039/B004766J
Publication status	Published - 2000

Keywords

trifluoroethanol
allylic alcohols
fragmentation
benzyloxy
allyloxy

Access to Document

10.1039/B004766J

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title = "Synthesis of α-hydroxy-β,β-difluoro-γ-ketoesters via [3,3]sigmatropic rearrangements",

abstract = "Readily available γ,γ-difluorinated allylic alcohols obtained from trifluoroethanol were esterified efficiently. Exposure to strong base (LDA) afforded the ester enolates, in which chelation both controlled configuration and stabilised against fragmentation, which were trapped as their silyl ketene acetals. Rearrangement occurred to afford base-sensitive acid products. Esterification under mild conditions afforded the purifiable methyl esters in which the masked ketone had been released. Educts with either a benzyloxy or an allyloxy group at the α-position could be deprotected releasing the alcohols.",

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author = "Michael Broadhurst and Brown, {Samantha J} and Jonathan Percy and Prime, {Michael E}",

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T1 - Synthesis of α-hydroxy-β,β-difluoro-γ-ketoesters via [3,3]sigmatropic rearrangements

AU - Broadhurst, Michael

AU - Brown, Samantha J

AU - Percy, Jonathan

AU - Prime, Michael E

PY - 2000

Y1 - 2000

N2 - Readily available γ,γ-difluorinated allylic alcohols obtained from trifluoroethanol were esterified efficiently. Exposure to strong base (LDA) afforded the ester enolates, in which chelation both controlled configuration and stabilised against fragmentation, which were trapped as their silyl ketene acetals. Rearrangement occurred to afford base-sensitive acid products. Esterification under mild conditions afforded the purifiable methyl esters in which the masked ketone had been released. Educts with either a benzyloxy or an allyloxy group at the α-position could be deprotected releasing the alcohols.

AB - Readily available γ,γ-difluorinated allylic alcohols obtained from trifluoroethanol were esterified efficiently. Exposure to strong base (LDA) afforded the ester enolates, in which chelation both controlled configuration and stabilised against fragmentation, which were trapped as their silyl ketene acetals. Rearrangement occurred to afford base-sensitive acid products. Esterification under mild conditions afforded the purifiable methyl esters in which the masked ketone had been released. Educts with either a benzyloxy or an allyloxy group at the α-position could be deprotected releasing the alcohols.

KW - trifluoroethanol

KW - allylic alcohols

KW - fragmentation

KW - benzyloxy

KW - allyloxy

U2 - 10.1039/B004766J

DO - 10.1039/B004766J

M3 - Article

VL - 2000

SP - 3217

EP - 3226

JO - Journal of the Chemical Society, Perkin Transactions 1

JF - Journal of the Chemical Society, Perkin Transactions 1

SN - 1472-7781

IS - 19

ER -