Formal synthesis of (-)-warburganal and synthesis of (+)-isodrimenin

The formal divergent synthesis of natural products (-)-warburganal and synthesis of (+)-isodrimenin has been developed from α-hydroxy β,γ-unsaturated aldehyde I, which was easily prepared from available (+)-sclareolide in 5 steps. Reduction of intermediate I to II <i>via</i> an aldehyde reduction provides a 10-step access to (-)-warburganal, while oxidation of I to III <i>via</i> allylic oxidation and <i>in situ</i> hemiacetalization facilitates a 9-step synthesis of (+)-isodrimenin.