Chemical shifts of the tertiary methyl groups in the nuclear magnetic resonance spectra of some limonoids. Part II

Abstract

Derivatives of khivorin lacking substituents at C-7 have been prepared; this allows calculation of the methy shift increments for substitution at this position. The results show dependence on substitution at positions 14 and 15, and the reason for this is discussed. The methyl group shifts of some other new limonoids are also recorded Two cases which do not agree with our calculations are described and reasons for the discrepancies are discussed.