The Stereochemistry of Dihydrolycorine.

Abstract

The epoxide (II), the monomethyl ether (III), and the monodesoxy derivative (IV) of dihydrolycorine were obtained from dihydrolycorine (I) via its monotosylate (Ic). It has been determined from the results of the ring-opening reaction of the above-mentioned epoxide that the two vicinal hydroxyl groups in (I) are trans and diaxial. Furthermore, by the elimination reaction of the hydroxyl function, (III) and (IV) are easily convertible to the corresponding unsaturated compounds (V) and (VI), respectively. On the basis of these findings, it may be suggested that the stereochemical structure of dihydrolycorine (I) can be represented as shown in (XII).