([5-13C] Tetrazol-5-yl)methyl ketones were prepared and subjected to oxidative fragmentation induced by lead tetraacetate. The resulting intermediate [1-13C]-3-oxoprop-1-en-1-ylidenes rearrange, depending on the relative migratory aptitudes of the benzoyl group and the ligands R, either to [3-13C]prop-2-yn-1-ones or to [2-13C]prop-2-yn-1-ones or to mixtures of the two isomers. The 1H and/or 13C NMR
([5- 13 C]四唑-5-基)制备并经受由四乙酸铅诱导的氧化断裂的甲基酮。将得到的中间体[1- 13 C] -3-氧代丙-1-烯-1- ylidenes重新排列,取决于苯甲酰基的相对迁徙性向和配体R,要么[3- 13 C]丙-2- yn-1-one或[2- 13 C] prop-2-yn-1-one或两种异构体的混合物。产物的1 H和/或13 C NMR光谱可以区分这三种情况。发现相对迁移能力为H> PhCO,4-MeOC 6 H 4 > 4-O 2 NC 6 H 4。