Straightforward synthesis of the strong ambergris odorant γ-bicyclohomofarnesal and its endo-isomer from R-(+)-sclareolide

γ-Bicyclohomofarnesal 1 and its endo isomer 5 were prepared in 47 and 26% overall yields, respectively, from commercial R-(+)-sclareolide (7), in a three-step sequence. The synthetic procedure involves the preparation of Weinrebʹs amide 9, dehydration of tertiary alcohol to form compounds 10 and 11, chromatographic separation and reduction with LiAlH4. This approach is simple and can compete with the syntheses previously reported for the preparation of these important compounds, both in overall yields and in the number of synthetic steps.