Synthesis and carbene decomposition of functionally substituted diazoacetate esters. 6. Propargyl diazoacetate

A synthesis of propargyl diazoacetate (I) was carried out and its chemical transformations were studied. The reaction of (I) in the presence of Rh(OAc)₂ at 25C with 1-pentyne gives the propargyl ester of l-propylcyclopropene-3-carboxylic acid in 80% yield, while reaction with 2,3-dimethyl-2-butene at 60C results in the propargyl ester of tetramethylcyclopropanecarboxylic acid in 10% yield. Compound (I) reacts under the same conditions (35–60C) with ether, CH₂Cl₂ and water, with the formation of propargyl esters of ethoxyacetic, 2,3-dichloropropionic, and a mixture of glycols and 2-[(propyn-2-yl)-oxycarbonyl]methoxy acetic acids in yields of up to 35%. A spontaneous oligomerization of (I) was observed as a result of a dipolar [1, 3]-cycloaddition of the CH=N₂ fragment of one molecule of (I) to the terminal triple bond of the second molecule with the formation of oligomers of 3-hydroxymethylpyrazole-5-carboxylic acid.For previous communication, see [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1051–1056, May, 1991.