SYNTHESIS OF OMEGA-ACETYL-ALPHA-METHYLENP OLYENE CARBOXYLIC ESTERS

The alpha-methylenpolyene carboxylic acids 1 and 2 are highly active a gainst Gram-positive bacteria. If this activity arises from an interfe rence with the cell membranes, then an abrupt change in biological pro perties is to be expected with growing chain length of simple model co mpounds. To make these tests possible, we describe here the synthesis of a series of homologue esters of type 40. Their synthesis was achiev ed by Wittig reactions of polyene alpha,omega-dialdehydes 6 with acety l-methylentriphenylphosphoran 5a and the protected carboxymethylmethyl en triphenylphosphonium salt 8.