Abstract
The route for the preparation of carbon-linked pyrone libraries
involving an optimized one-step reductive condensation between active
methylene compounds and aldehydes is described. The initial synthesis
of these analogues utilizing conventional alkylation methods proved
to be unsuitable for singleton or library application. The chemistry
was not only low-yielding but presented serious purification challenges.
The optimized route reported herein utilizes a Lewis base-borane
complex that acts in situ first as a catalyst for the condensation,
then as a mild reducing agent to cleanly yield the desired product
in a one-pot reaction.
Key words
Knoevenagel condensation - C-C bond formation - HCV polymerase inhibitor - dihydropyrone - amine-borane
reagents
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