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.