Abstract:[l-(Carbomethoxy) alkylidene]-5-vinyltetrahydrofurans which arise from preferential 0-alkylation upon cyclization of@-keto esters smoothly rearrange to the desired C-alkylation products, 2-(carbomethoxy)-3-~ inylcyclopentanones, with catalysis by Pd (0). With the methyl-substituted analogue, Le., 2-(5-vinyltetrahydrofuran-2-ylidene) propionate, the major product is (Z)-2-(carbomethoxy)-2-methyl-3-vinylcyclopentanone. On the other hand, 1-( ...
