Sterols in marine invertebrates. Part 42. Isolation, partial synthesis and structure determination of sterols with the four possible 23,24-dimethyl-substituted side chains
Using a Claisen ortho-ester rearrangement, the biogenetically important marinesterol dinosterol and its C-24 epimer were synthesized stereospecifically by a sequence which is also attractive for selective isotope labelling in the sidechain.