Synthesis of oxa-analogues of zearalanone

Abstract

The synthesis of macrocyclic lactones related to zearalanone is described. The reaction of salicylic acids with 1,9-dibromononane, 1,9-dichloro-5-oxanonane, and 1,9-dibromononan-5-one was used to prepare the corresponding lactones. Cyclisation of 2-(9-hydroxynonyloxy)benzoic acid, 4,6-dibenzyloxy-2-(9-hydroxynonyloxy)benzoic acid, and 4-benzyloxy-2-hydroxy-6-(9-hydroxy-5-oxodecyloxy)benzoic acid using diethyl azodicarboxylate–triphenylphosphine gave the corresponding lactones in moderate yield.