Conditions for a Rh(I)-catalyzed 2 + 2 + 1 cycloaddition reaction with methyl substituted allenes and alkynes

摘要

The direct installation of the C4 and C10 methyl groups present in the 6,12-guaianolide framework using a Rh(I)-catalyzed cyclocarbonylation reaction of methyl subsituted allenes and alkynes is described. High yields of bicyclo[5.3.0]decanes are afforded when low reaction concentrations involving syringe pump addition of the allene-yne to the catalyst are used.