New 8-alpha-13,14,15-tetra:hydroxy-labdane derivs. - are sclareolide intermediates obtd. in high yield from sclareol

摘要

8alpha,13,14,15-Tetrahydroxylabdane derivs. of formula (I) are new. In (I), R1 and R2 = H or 1-3C acyl. USE/ADVANTAGE - (I) are intermediates for sclareolid (II), which is useful in the prodn. of the odorant ambroxane. (I) are obtd. in at least 80% yield and provide better access to (II) than the processes known from US3050532, DE 3610063 and DE 3942358. In an example, (i) soln. of sclareol (III) (154g) in acetic acid (1.25 l) was treated at 45 deg.C with NaBO3.4H2O (385g), stirred at 70 deg.C, diluted (H2O), cooled and extracted. Extracts were washed neutralised, dried and evaporated to give, after recrystallisation (hexane) and vacuum drying, a mixt. of 8alpha,13,14-trihydroxy-15-acetoxylabdane and 8alpha,13,15-trihydroxy-14-acetoxylabdane (Ia) (167.5g; 87.5% yield); m.pt. 140-143 deg.C.