Hanishenols A-B, novel linear or methyl-branched glycerol enol ethers of the axinellid sponge Acanthella carteri (=Acanthella aurantiaca) from the Hanish Islands, Southern Red Sea

The axinellid sponge Acanthella carteri Dendy, 1889 (= Acanthella aurantiaca Keller, 1889) from the Hanish Islands, Yemen, on EtOH extraction followed by FC and HPLC purification gave the first example of branched glycerol enol ether, hanishenol B (3) alongside a major unbranched analogue, hanishenol A (1). Their structures were elucidated from NMR and MS spectra and through the ozonolysis product of 1, while the absolute configuration was assigned from exciton coupling with the dibenzoate derivative 2. (C) 1997, Published by Elsevier Science Ltd.