EFFICIENT SYNTHESIS OF 2-VINYL-GAMMA-BUTYROLACTONES AND 2-VINYL-GAMMA-BUTYROLACTAMS BY PALLADIUM-CATALYZED DECARBOXYLATIVE CARBONYLATION

4-Vinyl-1,3-dioxan-2-ones (cyclic carbonates) undergo decarboxylation-carbonylation by the catalysis of Pd(0) species under CO (in most cases, 1 atm) to provide 2-vinyl-gamma-butyrolactones in good yields. The course of the reaction of 6-vinyltetrahydro-2H-1,3-oxazin-2-ones (cyclic carbamates) depends on the substituent on the nitrogen atom. When it is H or Ts (and COPh), 2-vinyl-gamma-butyrolactams or 6-amino-3-hexenoic acid esters are obtained. Cyclic N-benzylcarbamates are unreactive. trans-2,3-Disubstituted lactones and lactams arise stereoselectively from carbonates and carbamates, irrespective of their stereochemistry, respectively.