Synthesis and PAF antagonist activity of some 2,5-diaryltetrahydrofurans incorporating PAF-like functional groups

Summary This paper describes the synthesis and structure-activity relationships of a series of 2,5-diaryltetrahydrofurans, as specific and potent antagonists at the rabbit washed platelet activating factor (PAF) receptor. The methoxyl groups in the known PAF antagonist L-652,731 were replaced with functional groups present in PAF and in the ‘PAF-like’ antagonists. Activity was generally retained or enhanced when one aryl ring in L-652,731 was elaborated; however incorporation of these functional groups into both of the aryl rings greatly reduced or abolished activity. These results are discussed in relation to a putative model for the PAF receptor.