R. Grigg et V. Savic, Synthesis of substituted alpha-methylene-gamma-butyrolactones from chloroformates via palladium catalysed cyclisation-anion capture, PHYS CHEM P, 2(23), 2000, pp. 2381-2382
Cyclisation of chloroformates onto proximate alkyne functionality in the pr
esence of a Pd(0) catalyst followed by anion capture affords alpha -methyle
ne-gamma -butyrolactone derivatives in moderate to good yields.