SYNTHESIS OF HETEROCYCLIC PLATELET-ACTIVATING-FACTOR ANALOGS

The synthesis of heterocyclic analogues of the platelet activating fac tor is described. The preparation starts with acylating rac-tetrahydro -1,3-thiazine-4-carboxylic acid ethyl ester, with palmitoyl chloride t o form the amide linkage. Following ester reduction, the phosphocholin e part is introduced via 2-chloro-2-oxo-1,3,2-dioxaphospholane and sub sequent ring opening with trimethylamine under pressure. Furthermore, the related L-thiazolidine analogue is prepared using the same procedu re. In addition the sulfinyl and sulfonyl derivatives of this compound are obtained by oxidation with 3-chloro-perbencoic acid. From one sul finyl intermediate the diastereomeres are separated and their conforma tions are determined by C-13-NMR spectroscopy