4 (85) of ethyl levulinate, which yields a mixture of both 3 and 4, the chemoselectivity is maintained, but the reaction is less regioselective. In spite of this, the internal olefin 4 is still the major component of the product mixture. l Since trimethylsilyl enol ethers are extremely useful synthetic reagentsY2 we felt that derivatives such as 1-4 which contain multiple but differentiated chemical functionality offered considerable synthetic potential. In this
