Synthesis of 1a,25-dihydroxyvitamin D3 analogues with a-hydroxyalkyl substituents at C12.

The Journal of steroid biochemistry and molecular biology

PubMedID: 23098691

Carballa DM, Zacconi F, Kulesza U, Mouriño A, Torneiro M. Synthesis of 1a,25-dihydroxyvitamin D3 analogues with a-hydroxyalkyl substituents at C12. J Steroid Biochem Mol Biol. 2013;13634-8.
Convergent syntheses of three new analogues of 1a,25-dihydroxyvitamin D3 with a-hydroxyalkyl substituents at C12 (4a-c) are described. The A-ring and triene system of each analogue were assembled by a tandem Pd-catalysed intramolecular cyclization and Suzuki-Miyaura coupling process. The stereoselective introduction of substituents at C12 was achieved by Johnson-Claisen rearrangement on allylic alcohol 15 as the key step. This article is part of a Special Issue entitled 'Vitamin D Workshop'.