13C-13C Coupling-Constants in Carboxylate Esters

Autor: M. Fortin, T. Morrison, J. Connolly, K. Pothier, M. Dinztner, M. Biondi, Ronald M. Jarret, Leonarda Cusumano
Rok vydání: 1993
Předmět:
Zdroj: Microchemical Journal. 47:187-192
ISSN: 0026-265X
DOI: 10.1006/mchj.1993.1032
Popis: Isotopic enrichment or a multipulse NMR experiment (INADEQUATE) was utilized to measure the 13 C- 13 C coupling constants for a collection of carboxylate esters. Significantly different values were measured for the C 2 C 3 bond of endo - and exo -2-norbornyl acetates. The 13 C- 13 C coupling constants for the CαCO bond of substituted methyl and ethyl acetates (YCCO 2 R: Y = Br, Cl, SH, CN, etc.) were in the range of 56 to 65Hz; the magnitude of J CC is substantially higher when the hybridization of Cα is sp 2 (as with benzoates and acrylates). The carbonyl carbons also displayed long range 13 C- 13 C couplings of 2.5 to 7.2 Hz.
Databáze: OpenAIRE