Summary Two 10-membered ring lactones 7 and 11 from the metasternal secretion of the eucalypt longicorn Phoracuntha synonyma have been synthesized by the following method. Reaction of the dilithium derivative of 4-pentynoic acid (3) with 4-tetrahydropyranyloxy-1- pentylbromide (2), followed by removal of the protecting group and by esterification with diazomethane, gave methyl 9-hydroxy-4-decynoate (4; s. Scheme 1). Partial ...
