Oxidative alkaline cleavage of the title compound 3 gave unexpectedly in high yields the α-keto acid 9a instead of the aldehyde acid 5 (or its tautomer 7). The latter could be prepared via regioselective mono-ketalisation of compound 3. The structure assignment of 9, and differentiation between 5/7 and the isomer 10, were effected using natural abundance 13C13C coupling techniques.
出乎意料的是,标题化合物3的氧化碱性裂解产生了高产率的α-
酮酸9a,而不是醛酸5(或其互变异构体7)。后者可以通过化合物3的9所述的结构分配的区域选择性单
缩酮化和分化5/7和异构体10之间来制备,以天然丰度实现13 C 13种C偶联技术。