Ring expansion of cyclopropylmethanols to cyclobutanes—an enantioselective total synthesis of (R)-(+)-dodecan-5-olide, and (S)-(+)- and (R)-(–)-5-[(Z)-dec-1-enyl]dihydrofuran-2(3H)-one

Abstract

A novel and convenient route to chiral cyclobutanones (8) and (9) by ring expansion of the Cyclopropylmethanols (6) and (7) was developed, leading to an enantioselective total synthesis of (R)–(+)-dodecan-5-olide (25), and (S)-(+)- and (R)–(-)-5-[(Z)-dec-1-enyl]dihydrofuran-2(3H)-one (35) and (36)(the pheromone of the Japanese beetle).