Homoisoflavonoids and Related Compounds. II. Isolation and Absolute Configurations of 3, 4-Dihydroxylated Homoisoflavans and Brazilins from Caesalpinia sappan L.

Abstract

Three new phenolic compounds, 3'-Ο-methylsappanol, 3'-Ο-methylepisappanol and 3'-Ο-methylbrazilin, were isolated from Sappan Lignum, the dried heartwood of Caesalpinia sappan. The absolute configurations of sappanol, episappanol, 3'-deoxysappanol, 3'-Ο-methylsappanol, 3'-Ο-methylepisappanol, brazilin and 3'-Ο-methylbrazilin were determined by means of Horeau's partial resolution method and chemical correlations.
Sappanol, episappanol, 3'-deoxysappanol, 3'-Ο-methylsappanol and 3'-Ο-methylepisappanol form a novel class of homoisoflavonoids.