Diterpenoids. XI. Manool trihydrochloride

Abstract

The crystalline trichloro compound obtained from sclareol (I), manool (VI), and the manoyl oxides (IX, X) by addition of hydrogen chloride has the 8R,13,16-trichlorolabdane structure (XII). The compound is a 1 : 1 mixture of C13 epimers which are inseparable by normal means. However, addition of the trichloride to an equal amount of the antipodal mixture obtained from the enantiomeric manoyl oxide [(-)X] readily gave two separable racemates.