diazoacetate

Noun

 * 1)  Any salt or ester of diazoacetic acid; the esters react with alkenes to form cyclopropane derivatives
 * Aldrichimica Acta Volume 30 No 4 (pdf) from Sigma-Aldrich
 * Considering the range of chiral catalysts that are available for diazoacetate decomposition, the development of reaction conditions for asymmetric vinylcarbenoid cyclopropanations had initially been considered to be relatively straightforward.