Abstract
Stirring α,β-unsaturated α-diketones in the presence of activated silica gel results
in cyclization to α-hydroxycyclopentenones in good yield. The reaction is sensitive
to the mode of stirring and proceeds more rapidly in the presence of triethylamine.
This is consistent with a Nazarov reaction proceeding through the enol tautomer of
the α-diketone.
Key words
diketones - cyclizations - Nazarov reactions - silica gel - rearrangements
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