6,6-Dimethyl-hept-1-en-4-yn-3-ol: A useful model for investigation of the effect of trifluoroacetic acid on the stereoselectivity of allylic rearrangement

Reactions of 6,6-dimethyl-hept-1-en-4-yn-3-ol with an excess of trifluoroac etic acid or equivalent amount of trifluoroacetic anhydride have effected s imultaneous acylation and allylic rearrangement providing (E)-6,6-dimethyl- hept-2-en-4-yn-1-ol trifluoroacetate with excellent stereoselectivities and yields. Systematic investigation of the product distribution as a function of the molar ratio and the reaction time was carried out for optimization of the reaction conditions.