Synthesis and carbene decomposition of functionally substituted diazoacetate esters. 6. Propargyl diazoacetate
摘要:
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 25-degrees-C with 1-pentyne gives the propargyl ester of 1-propylcyclopropene-3-carboxylic acid in 80% yield, while reaction with 2,3-dimethyl-2-butene at 60-degrees-C results in the propargyl ester of tetramethylcyclopropanecarboxylic acid in 10% yield. Compound (I) reacts under the same conditions (35-60-degrees-C) with ether, CH2Cl2 and water, with the formation of propargyl esters of ethoxy-acetic, 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.
TMSCl Promoted Direct Conversion of Cyclic Anhydrides to (Un)Symmetric‐Diesters/Amide Esters
作者:Meera Johny、Amuda Manikandan、Goreti Rajendar
DOI:10.1002/asia.202301017
日期:2024.2
A mild, novel, and efficient silyl-promoted conversion of cyclic anhydride to diesters and amide esters. The reaction follows a two-step process, ring opening of anhydride by amine or alcohol following esterification. The reaction was carried out in the presence and absence of base. The method has broad substrate scope and is applicable for the synthesis of commercial plasticizers.