Abstract

Selenourea reacts with dialkyl acetylenedicarboxylates under solvent-free conditions to form 1:1 adducts, which undergo a cyclization reaction to produce alkyl Z-2-(2-amino-4-oxo-1,3-selenazol- 5(4H)-ylidene)acetates, in good yields. The stereochemistry of the ethyl Z-2-(2-amino-4-oxo-1,3- selenazol-5(4H)-ylidene)acetate was established by X-ray single crystal structure analysis. The reaction is completely stereoselective.