| 摘要 |
Stereospecific process for the prodn. of (-)3a,6,6,9a-tetramethyl-perhydronaphtho(2,1-b)furan of formula (Ia) comprises dehydration and cyclisation of molten decahydro-2-hydroxy-2,5,5,8a-tetramethyl-1-naphthalene ethanol (II) (ambroxdiol) in the presence of 10-100 wt.%, (based on (II)) of a active acidic alumina at 80-200 degrees C. The acidic alumina is commercially available for column chromatography. |
