addition of methyl diazoacetate (I) to the carbonyl group of the substituted propyn-1-als RCCCHO (II) (R = alkyl, Alk3Si, Et3Ge) to give the corresponding methyl esters of 2-diazo-3-hydroxy-4-pentyn carboxylic acid RCCCH(OH)C(N2)COOMe (III) have been found. Shielding of the triple bond in II by the bulky R group or complexation with dicobaltoctacarbonyl, the presence of strong electron acceptor
未催化,选择性地将重氮乙酸甲酯(I)加至取代的丙炔基1-丙二醛RCCCHO(II)(R =烷基,Alk 3 Si,Et 3 Ge)的羰基上的最佳条件已经发现2-重氮-3-羟基-4-戊炔羧酸RC = CCH(OH)C(N 2)COOMe(III)的相应甲酯。通过庞大的R基团屏蔽二代中的三键,或与二钴八羰基二钴络合,在二代的3位上存在强电子受体(4-NO 2 C 6 H 4),并且溶剂的极性低在选择性羟醛缩合中。γ-羟基丙醛R 1 R 2的反应具有重氮乙酸甲酯的C(OH)= CCHO也通过醛醇型加成而进行,并且涉及两个丙炔分子,形成二炔基重氮四环(VIII)。将重氮乙酸甲酯的β加成到三烷基甲硅烷基或-锗基丙炔中的三键上,得到异构的甲酰基吡唑IV和V.IV的4位上含Si或Ge的取代基的存在会促进它们的二聚为三环半胱氨酸,VI。