Synthesis of functionalised bicyclic α-methylene-γ-butyrolactones from 2, 3-cyclohexene acetal via radical cyclisation approach

2, 3-Cyclohexene acetal, wherein the acetal wherein the acetal lunctionality is derived from 2R, 3R(+)-tartaric acid, has been transformed regioselectively into functionalised bicyclic α-methylene-γ-butyrolactoes via radical cyclisations. The radicals were derived from n-bu3SnH reactions with secondary bromides and a tertiary nitro compound