Isopropenyl acetate reaction with triethylmethoxytin

These compounds have been synthesized by several methods. A convenient method is by the interaction of trialkylmethoxytin compounds with enol acetates. For example, reaction of triethylmethoxytin (73) with isopropenyl acetate (74) gives the tin(IV) enolates as a mixture of 0- and C-isomers (75) and (76) (Scheme 2S). The exchange reaction appears to maintain the regiochemistry of the starting enol ester. Thus, reaction of 2-methyl-1-acetoxycyclohexene with tributylmethoxytin gives compound (77). On the other hand, the regioisomer (78) has been generated in situ by treatment of the precursor lithium enolate with tri-n-butylstannyl chloride (Scheme 26). ... 

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