SYNTHESIS OF AMBROX(R) FROM (-)-SCLAREOL AND (-CIS-ABIENOL())

Short and efficient syntheses of (-)-Ambrox(R) (12) from (-)-sclareol (1) and (+)- cis-abienol (11) are described. In contrast to previously described procedures, the transformation of 1 to 12, involving in the key step, an oxidative degradation by catalytic osmium tetroxide, in the presence of sodium periodate, has the advantage of using the more suitable sodium borohydride, as the reducing agent. The isolation and characterization of some reaction intermediates allowed us to confirm the degradation mechanism.