| abstract |
A process for the stereoselective preparation of (-)3a,6,6,9a-tetramethylperhydronaphtho[2,1-b]furan of the formula Ia ##STR1## by dehydration and cyclization of decahydro-2-hydroxy- 2,5,5,8-tetramethyl-1-naphthaleneethanol using solid acidic catalysts, wherein the decahydro-2-hydroxy- 2,5,5,8-tetramethyl-1-naphthaleneethanol is heated in the molten state at from 80° to 200° C. in the presence of from 10 to 100% by weight, based on the diol, of an active acidic aluminum oxide commercially supplied for (preparative) column chromatography. |