Synthesis and protein kinase C inhibitory activities of indane analogs of balanol

Regio- and stereoisomeric indane analogs (4–6) of balanol (−)-1, a potent protein kinase C (PKC) inhibitor, were synthesized in which the perhydroazepine of balanol was replaced by an indane nucleus. Analog (−)-4 and its racemic regioisomer 6 were found to have highly potent PKC inhibitory activities. In addition, compound (−)-4 displayed excellent kinase selectivity for PKC over PKA.