REARRANGEMENT OF ESTERS IN GAS PHASE .2. SUBSTITUENT EFFECTS ON RATE OF ISOMERIZATION OF ALLYLIC ESTERS

The earlier studies on rearrangement of crotyl esters are extended to the study of α- and γ-trifiuoromethylallyl trifluoroacetates (IV and V), allyl-α-d2 trifluoroacetate (I), allyl−18O trifluoroacetate (III), α,β-dimethylallyl acetate (VII), and α,γ-dimethylallyl acetate (X). In some cases a minor but detectable rearrangement to cis- as well as trans-γ-substituted allyl derivatives is observed. The rate of rearrangement of allyl acetate is within experimental error the same whether followed by deuterium or 18O labeling. The results are consistent with the transition state with carbonium carboxylate character proposed earlier. © 1968, American Chemical Society. All rights reserved.