Synthesis of Four Diastereoisomers of Dihydrorotenone

Synthesis of Rotenoids II

Abstract

By the catalytic hydrogenation of l-dihydrodehydrorotenone, a stereoisomer of dihydrodesoxy-rotenone and two of dihydrorotenone were prepared and termed as dihydrodesoxyallorotenone, dihydroallorotenone-I and -II respectively. Since the catalytic hydrogenation of ethylenic bonds proceeds by cis-addition, it seems reasonable that dihydroallorotenone-I and -II have cis-junction of the rings at C₁₂ and C₁₃, and accordingly l-dihydrorotenone and d-dihydroepirotenone have trans-junction.