Use of selective heteronuclear 13c1h noe measurements. a second note of warning on the assignment of structure to the products formed in the reactions between 4-hydroxy-2 -pyran-2-ones and carbonyl compounds.
作者:J. Cervello、M. Gil、P. de March、J. Marquet、M. Moreno-Mañas、J.L. Roca、F. Sanchez-Ferrando
DOI:10.1016/s0040-4020(01)86824-1
日期:——
translactonization during condensation of 4-hydroxy-6-methyl-2H-pyran-2-one, 1, or 4-hydroxycoumarin, 4, with carbonyl compounds are desoribed. The structure of previously misassigned products 6a,b is proven by NMR techniques. Application of the HETNOE method to the distinction between structures 9 and 10 is demonstrated.