A New Convenient Synthetic Method for 3-Allyl-1,1,1-trifluoroacetylacetone and its Derivatives

Abstract

Starting from the dimethyl acetal of acetone several 3-allyl-1,1,1-trifluoroacetylacetones (1) were synthesized in high yields by treatment with trifluoroacetic anhydride, ether exchange reaction of the resulting β-trifluoroacetyl-α-methylvinyl ether with allyl alcohols in the presence of silica gel, followed by Claisen rearrangement. Reaction of 1 with hydrazine hydrate gave an allyl-substituted pyrazole bearing a trifluoromethyl group in high yield.