SYNTHESIS OF (+)-, (-)- AND (+/-)-7'-HYDROXYABSCISIC ACID

Article abstract of DOI:10.1016/S0040-4020(01)86392-4

A total synthesis of 7'-hydroxyabscisic acid (1), a putative metabolite of the plant hormone abscisic acid (ABA), is described.The key intermediate in the twelve step synthesis is 2-t-butyldimethylsiloxymethyl-4,4-ethylenedioxy-6,6-dimethylcyclohex-2-en-1-one (5) which contains the desired masked hydroxyl group at the C-7'position of ABA.The final transformation in the synthesis, the hydrolysis of the methyl ester of 1 is readily accomplished with porcine liver esterase.Optically pure (+)- and (-)-forms of 1 are obtained by resolution of the silyl ether methyl ester by HPLC on a chiral column.