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

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

Research output: Contribution to journalArticle

27 Citations (Scopus)

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.
LanguageEnglish
Pages3217-3226
Number of pages10
JournalJournal of the Chemical Society, Perkin Transactions 1
Volume2000
Issue number19
Early online date11 Sep 2000
DOIs
Publication statusPublished - 2000

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Esters
Trifluoroethanol
Acetals
Esterification
Chelation
Ketones
Alcohols
Acids
ketene
allyl alcohol

Keywords

  • trifluoroethanol
  • allylic alcohols
  • fragmentation
  • benzyloxy
  • allyloxy

Cite this

Broadhurst, Michael ; Brown, Samantha J ; Percy, Jonathan ; Prime, Michael E . / Synthesis of α-hydroxy-β,β-difluoro-γ-ketoesters via [3,3]sigmatropic rearrangements. In: Journal of the Chemical Society, Perkin Transactions 1. 2000 ; Vol. 2000, No. 19. pp. 3217-3226.
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author = "Michael Broadhurst and Brown, {Samantha J} and Jonathan Percy and Prime, {Michael E}",
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Synthesis of α-hydroxy-β,β-difluoro-γ-ketoesters via [3,3]sigmatropic rearrangements. / Broadhurst, Michael; Brown, Samantha J ; Percy, Jonathan; Prime, Michael E .

In: Journal of the Chemical Society, Perkin Transactions 1, Vol. 2000, No. 19, 2000, p. 3217-3226.

Research output: Contribution to journalArticle

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

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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

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