Preparation of (−)-guaia-1(10),11-dien-15,2-olide and (−)-2α-hydroxyguaia-1(10),11-dien-15-oic acid, fragrant sesquiterpenes in agarwood (Aquilaria agallocha Roxb.)
The fragrant sesquiterpene (−)-guaia-1(10),11-dien-15,2-olide (8), isolated from agarwood (Aquilariaagallocha Roxb.), was synthesized starting from (−)-1,10-epoxybulnesene, which is readily available from α-bulnesene in patchouli oil. The absolute configuration of the natural 8 was established by direct comparison of its optical rotation with that of the synthesized 8. It was found that (−)-2α-hydroxyguaia-1(10)
Abstract Three new sesquiterpenes, (−)-guaia-1(10),11-dien-15-al, (−)-selina-3,11-dien-9-one, and (+)-selina-3,11-dien-9-ol, have been isolated from Aquilaria agollocha (agarwood). Their structures have been established on the bases of detailed spectroscopic analyses and synthesis. The odoriferous properties of these compounds are also described.