The I3C NMR spectra of 26 dihydroxy steroids and 10 acetylated derivatives have been obtained and assigned.It was found that only for compounds with 1,2or 1,3-dihydroxy groups are there significant differences between the observed chemical shifts and those calculated assuming additivity of the substituent effects found for the monosubstituted compounds. When there is steric interaction between the functionalities the deviation from additivity can be rationalized by considering the nature of the steric interactions which are introduced. It is demonstrated that in many cases the effect of OH-OH interactions can be approximated by the magnitude and direction of analogous OH-C or C-C interactions. Significant deviations from additivity were also found for a few compounds with no steric interaction between the substituents (1,3-trans and 1,e-diaxial diols). An upfield 1,3-syn-diaxial6 substituent effect is reported.
Diaporthe celastrina, ein Pilz, dessen Aktivität gegenüber Steroiden bislang noch nicht bekannt war, hydroxyliert eine Reihe von dioxygenierten 5α‐Androstanen (Tabelle) im allgemeinen in α‐Stellung.
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