WALLIFOLIOL, A TAXOL CONGENER WITH A NOVEL CARBON SKELETON, FROM HIMALAYAN TAXUS-WALLICHIANA

A new taxoid, wallifoliol [3], has been isolated, along with five know n taxoids (taxol, cephalomannine, 10-deacetylbaccatin III, brevifoliol , 2-acetoxy brevifoliol = taxchinin A) from extracts of the needles of Himalayan Taxus wallichiana. The structure of wallifoliol has been as signed primarily from nmr studies. Wallifoliol [3] is assigned a struc ture in which rings A and B of the taxane system have undergone putati ve rearrangements producing a novel skeleton. Wallifoliol is the first diterpene to be found in nature with this particular 5/6/6/6/4 ring s ystem.