Fused phosphono substituted O-, and N-heterocycles via condensative cyclisation reactions of α-phosphonyl carbanions with 4-thiazolidinones

Phosphono substituted-thiazolones 5a,b together with fused phosphono-pyran-5-ones 9a,b and the diolefins 8a-d were regioselectively prepared in, reasonable yields from). the reactions of 5-arylidene-4-thiazolidinones 1a,b with phosphonoacetates 2a,b. Conversely, Michael addition products 11a,b (similar to30%)) along with. the phosphono substituted-thiazole derivatives 12ab (similar to33%) were obtained from treating 1a,b with cyanomethylenphosphates (2c). The reactions of 1a,b with vinylphosphate 2d proceed with phase-transfer catalysis, yielding the corresponding 2-thioalkyl-derivatives 14a,b and phosphonates 13a,b.