NEW FUNCTIONALIZED HORNER-WADSWORTH-EMMONS REAGENTS - USEFUL BUILDING-BLOCKS IN THE SYNTHESIS OF POLYUNSATURATED ALDEHYDES - A SHORT SYNTHESIS OF (+/-)-(E,E)-CORIOLIC ACID

The new Horner-Wadsworth-Emmons reagents 4 and 5 transform carbonyl compounds into 2,4-pentadienals and 3-methyl-2,4-pentadienals, respectively. Reagent 4 gives good yields of the desired products with a variety of aldehydes and ketones; reagent 5 generally gives good yields with aldehydes, but gives lower yields with ketones. The reactions proceed under mild conditions and give the products as predominantly 2E,4E isomers, with moderate to good stereoselectivity. In general, pure samples of the 2E,4E-dienals can be obtained after chromatography. Reagents 4 have been used in the key step in a short synthesis of (±)-13-hydroxy-9(E),ll(E)-octadecadienoic acid ((E,E)-coriolic acid, 45). © 1990, American Chemical Society. All rights reserved.