Natural acetylenes. Part XXXIX. Synthesis of methyl [1,9-14C]-, [9-14C]-, and [10-3H]-crepenynate, methyl [9-14C]- and [10-3H]-linoieate, and methyl [9-14C]- and [10-3H]-oleate
Abstract
Specifically labelled methyl crepenynate and oleate have been synthesised from the C9 phosphoranes, Me[CH2]4·CC·CH2·CHPPh3 and Me[CH2]7·CHPPh3, respectively, and the C9 aldehyde ester, OCH·[CH2]7·CO2Me; methyl linoleate has been obtained by partial hydrogenation of the crepenynate. Carbon-14 was introduced into the C18 esters via the [9-14C]- and [1,9-14C]-aldehyde esters, and tritium via a reaction of the phosphoranes with tritiated methanol. Several routes to the labelled C9 aldehyde ester are described.