Total Synthesis of Dictamnol, a Trinor-Guaiane Type Sesquiterpene from the Roots of Dictamnus dasycarpus TURCZ.

Abstract

Dictamnol (1), a trinor-guaiane type seequiterpene from the roots of Dictamnus dasycarpus TURCZ., was synthesized from 4α-acetoxy-3, 4, 4a, 5, 6, 8aβ-hexahydro-4aα-methyl-2H, 8H-naphthalene-1, 7-dione (3) by the utilization of an intramolecular base-induced rearrangement with sodium tert-amylate as a key step (27→28). Compound 3 was prepared from a chiral dione, (S)3, 4, 8, 8a-tetrahydro-8aα-methyl-2H, 7H-naphthalene-1, 6-dione (2) according to the procedure of de Groot et al. [J. Org. Chem., 48, 4380 (1983)] and was transformed into dictamnol (1) via 22, 23, 24, 26, 27, 28, and 30. Thus, the absolute configuration of dictamnol is as represented by formula 1.