A concise enantiocontrolled total synthesis of (−)-α-bisabolol and (+)-4-epi-α-bisabolol

Abstract

The regiocontrolled hydrogenation of the cyclohexadiene 6, synthesised from the chiral cyclobutanone 3 was effectively achieved with [1,4-bis(diphenylphosphino)butane](1,5-cyclooctadiene)rhodium (1) tetrafluoroborate as catalyst to give the olefins 7 and 8 which were converted into (−)-α-bisabolol 1a and (+)-4-epi-α-bisabolol 15 via 9 and 10, 11 and 12, and 13 and 14.