Chemistry of the Podocarpaceae. XXII. Aspects of the chemistry of Totara-8,11,13-trien-13-ol

Abstract

Attempts have been made to effect fragmentation reactions with bromo- tetralone systems related to 6α-bromo-13-hydroxytotara-8,11,13-trien-7- one (VII), a compound which affords a secoditerpenoid (IX) when treated with DMSO-NaHCO₃. On treatment with sulphuric acid in acetone, the mono- epoxide derivative (XXVIII) of the methyl ether of the secoditerpenoid undergoes a novel aromatization to a naphthalenic aldehyde (XXXI) by successive transannular cyclization and fragmentation reactions.     A 7β-hydroxy configuration has been confirmed for the major product from reduction of 13-acetoxytotara-8,11,13-trien-7-one (VIII) with lithium aluminium hydride. 13-Methoxytotara-8,11,13-triene (II) has been deisopropylated and then subjected to Birch reduction in an attempt to effect a high yield conversion into (+)-podocarp-8(14)-en- 13-one (XXXVII), a potentially useful intermediate for synthesis.