Use of the two enantiometers of 7,7-dimethylbicyclo[3.2.0]hept-2-en-6-one to form complementary optically active synthons in a convergent synthesis of leukotriene-B4

Abstract

The acetate (±)-4 was resolved by an enantioselective hydrolysis catalysed by porcine pancreatic lipase. The resultant alcohol (–)-3 and the optically active ester (+)-4 were converted into the ketones (+)-2 and (–)-2 respectively. The ketone (+)-2 was elaborated to produce the diester 9 while the ketone (–)-2 was transformed into the phosphonium salt 21. A Wittig reaction between 9 and 21, followed by deprotection and chromatography furnished leukotriene-B₄.