Stereochemistry of some Altersolanol B Derivatives and their Correlation with Bostrycin

The results of a complete analysis of the proton spectra of altersolanol B acetonide indicate that this compound exists preferentially in the half-chair conformation corresponding to that favored by the parent pigment in the solid state, as shown by previous X-ray studies. In contrast, the triacetate derivative apparently adopts the alternative half-chair conformation.