Activated lactams. VI. The cycloaddition reaction of cyclic ketene-S,N-acetals with dimethyl acetylenedicarboxylate.

Gallium tribromide catalyzed coupling reaction of alkenyl ethers with ketene silyl acetals.

Trimethyl Phosphite Mediated Simple Synthesis of Coumarins and Azacoumarins Through the Reaction of Phenols or Hydroxypyridines and Dimethyl Acetylenedicarboxylate (DMAD) or Diethyl Acetylenedicarboxylate (DEAD)

Protonation of the reactive intermediate produced in the  reaction between trimethyl phosphite and dimethyl acetylenedicarboxylate or diethyl acetylenedicarboxylate by resorcinol, 5-methylresorcinol, 2,5-dihydroxyacetophenone, 4-chloro-2-methylphenol, 4-chloro-3,5-dimethy-lphenol, 4-hydroxypyridine, 2-hydroxypyridine, 3-hydroxypyridine, or 8-hydroxyquinoline leads to vinylphosphonium salts,...

Diastereoselective synthesis of potent antimalarial cis-β-lactam agents

Fifteen novel β-lactams bearing the N-ethyl tert-butyl carbamate group 5a-o and fifteen N-(2-aminoethyl) β-lactams 6a-o were synthesized by the ketene-imine [2+2] cycloaddition reaction (Staudinger ). The cycloaddition reaction was found to be totally diastereoselective leading exclusively to the formation of the cis-β-lactam derivatives. These newly synthesized β-lactams were evaluated for the...

PREPARATION OF (CHLOROCARBONYL) PHENYLKETENB AND ITS CYCLOADDITION REACTION WITH BENZALDEHYDEV

Meldrum's acid, 2'5-diphenyl-1'3-dioxane-4'6-dione, was produced by [2+2] cycloadditions of the (chlorocarbony1)phenylketene with benzaldehyde. Acid hydrolysis of the meldrum's acid regenerated benzaldehyde and also yielded phenylacetic acid as the final product

Diastereoselective synthesis of potent antimalarial cis-β-lactam agents

Fifteen novel β-lactams bearing the N-ethyl tert-butyl carbamate group 5a-o and fifteen N-(2-aminoethyl) β-lactams 6a-o were synthesized by the ketene-imine [2+2] cycloaddition reaction (Staudinger ). The cycloaddition reaction was found to be totally diastereoselective leading exclusively to the formation of the cis-β-lactam derivatives. These newly synthesized β-lactams were evaluated for the...