Abstract
Details and methodological comparisons are presented on the preparation of a norbisabolide γ-lactone analogue (4) via dichloroketene cycloaddition to limonene followed by regioselective Baeyer-Villiger oxidation (CH3CO3H) of the α,α-dichlorocyclobutanones 3 and C-Cl reduction (Zn/HOAc). The sequence of reduction followed by oxidation (HOCI) applied to 3 produced 4 in much better yield.