James Rawlinsona, Andrew F. Parsonsa and Mark Healyb a Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK b GlaxoSmithKline Research and development Ltd.

There are about 60 bi- and tri-cyclic natural products, which make up the cannabinoid family. Pharmacological effects observed due to some cannabinoids include analgesic, antiemetic, anti-inflammatory, bronchodilatory and anticonvulsant among others. Therefore an effective general synthesis of cannabinoids (both natural and synthetic) would be useful to aid building up libraries to test for biological activity.

In general, the cannabinoid structure consists of a variously substituted aromatic ring (A), a dimethylpyrane ring (B) and a variously unsaturated cyclohexyl ring (C). A representative example includes Δ ⁹ -THC (shown below).

Initial work will concentrate on formation and reaction of diene precursors with phosphites (which form phosphonyl radicals when initiated), which will help establish a method for the formation of the cannabinoid B-ring.

© Department of Chemistry, University of York.