Convergent syntheses of three new analogues of 1α,25-dihydroxyvitamin D3 with α-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'.
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