The synthesis of naturally occurring 4-alkyl- and 4-alkenyl-γ-lactones using the asymmetric reducing agent -3-pinanyl-9-borabicyclo[3.3.1]nonane

4-Hydroxy-2-alkynoates of high enantiomeric purity, available from the reduction of the corresponding ketones with B-3-pinanyl-9-BBN, are converted to 4-substituted-γ-lactones found in beetle and deer pheromones.