The synthesis of (Z)-trisubstituted allylic alcohols by the selective 1,4-hydrogenation of dienol esters: improved synthesis of (-)-β-santalol.
(E)-Trisubstituted allylic alcohols are commonly prepared from the corresponding (E)-enals, themselves readily accessible by a simple aldol condensation reaction. We demonstrate that these very same (E)-enals can be converted into (Z)-trisubstituted allylic acetates (and thus alcohols) by a ruthenium-catalyzed 1,4-hydrogenation of the corresponding dienol acetates. This simple solution to a long-lasting problem was applied to an industrially feasible synthesis of (-)-β-santalol.
Firmenich SA, Corporate R&D Division, P. O. Box 239, CH-1211 Geneva 8, Switzerland. charles.fehr@firmenich.com
Charles
C
Fehr
Iris
I
Magpantay
Magali
M
Vuagnoux
Philippe
P
Dupau