New Syntheses of (±)-Ambrox, (±)-Ambra Oxide and Their Stereoisomers

Abstract

New and efficient syntheses of (±)-ambrox (1a), (±)-ambra oxide (2a) and their Stereoisomers (1b, 2b-c), amber-like odorous compounds, are described. Starting from dihydro β- and α-ionone (5, 12), these substances were obtained in only a few steps via stereoselective acid-catalized cyclization of monocyclodienoic acid (7a-b, 11a-b, 15a).