Terpenoids-LXI: conversion of eudesmol to di- and tetrahydrocostol

Abstract

Dihydro-β-eudesmol (IV), obtained by catalytic hydrogenation of β-eudesmol (II), on pyrolysis via the benzoate gives dihydro-β-selinene (V). Its epoxyderivative (VI) is converted on treatment with acetic acid to the hydroxy acetate (VII), the benzoate of which on pyrolysis, followed by saponification, affords dihydrocostol (XI), converted by hydrogenation to tetrahydrocostol (XII). The alcohol (XI) is not identical with agarol to which the same stereoformula has been assigned previously. These results would necessitate a re-examination of the structure and stereochemistry of agarol which has already been undertaken.