P-5 ポリハイドロキシステロイドの^<13>C NMRの加成則について(ポスター発表の部)

概要

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It was assumed that the additivity relationships of the δ_c val-ues in the carbon-13 nuclear magnetic resonance spectra of polyhydroxy 5α,14α-steroids could be equated with the sum total of those of individual 1,2-and 1,3-glycol types involved in the molecule. The differences in the δ_c values (Δδg), reported for various types of glycols from those derived by addition of monohydroxy substituent effects, were converted to dihydroxy steroid parameters (Table 1). Several supplementary data for 8β-hydroxy steroids are derived. The dihydroxy steroid parameters were applied to 14 different types of known polyhydroxy steroids (6-19, Chart 3) and the calculated δ_c values were derived (Table 3). The results indicate that within reasonable deviations this method generally gives the predicted δ_c values of polyhydroxy steroids, except for those having an excessively severe steric hindrance, such as found in 4β, 6β,8β, 15β-tetrahy-droxylated steroid 19.
天然有機化合物討論会の論文
1994-09-20