Diels-Alder Reactions of 1,3-Cyclohexadienes and 3-(Trimethylsilyl)propynoates. A New Synthesis of Ortho-(Trimethylsilyl)benzoate Esters.

Abstract

Diels-Alder reaction of 1,3-cyclohexadienes and 3-(trimethylsilyl)propynoates yields ortho-(trimethylsilyl)benzoates.

Notes

I-Methoxy-1,3-cyclohexadiene is available from Aldrich Chemical Co., Inc. as a 65:35 mixture of 1-methoxy-1,3-cyclohexadiene and 1-methoxy-1,4-cyclohexadiene. A small amount (9% yield) of an inseparable 1:1 mixture of 6 and 7 was also isolated from the reaction mixture. Compounds 6 and 7 presumably arise from reaction of 2-methoxy-1,3-cyclohexadiene formed by isomerization of 1-methoxy-1,4-cyclohexadiene under the reaction conditions.