The partial synthesis of dihydroisohibaic acid (22b) and isohibane (22f) from isop: maric acid is described. The stereochemistry of the intermediates has been elucidated. Cationic cyclization of methyl 20-hydroxy-A'-and-AB-dihydroisopimarate alkyl and arylsulfonates (8d and 9d) did not furnish derivatives of isohibane, but led to compounds of type 10 with rearrangement of the carbon skeleton.
