Lipase mediated resolution of cis- and trans-linalool oxide (pyranoid)

The four isomeric forms of the flavour linalool oxide (pyranoid) were synthesized starting from the inexpensive monoterpene terpinolene. The key steps of the process include mCPBA epoxidation of the starting diene, alumina-catalysed rearrangement of the obtained diepoxide and the diastereoselective reduction of the ketone 2,2,6-trimethyl-6-vinyldihydro-2H-pyran-3(4H)-one. The resulting racemic cis- and trans-linalool oxides were resolved through an enzyme-mediated acetylation procedure. More specifically, we found that Candida rugosa lipase and lipase PS are the catalysts of choice for the resolution of cis- and trans-linalool oxide, respectively.