Optical resolution of 7‐oxabicyclo[2.2.1]hept‐21‐ene derivatives. Diastereoselectivity in the formation of cyanohydrine‐brucine complexes

A new, practical method for the optical resolution of bicyclic ketones if illusttrated by the preparation of (+)‐(1 R ,4 R )‐7‐oxabicyclo[2.2.1]bept‐5‐en‐2‐one ((+)‐ 1 ) and (+)‐(1 R , 2 S ,4 R )‐2‐cyano‐7‐oxabicyclo[2.2.1]hept‐5‐en‐2‐yul acetate ((+)‐ 4 ). It involves the diastereoselective formation of a brucine complex with the corresponding cyanhydrine mixture.