Abstract

In the past ten years, the development of efficient methods for the synthesis of A-ring 1,7-enyne synthons is one of the most fascinating aspects in the area of active vitamin D3 research. Many concise and practical approaches to construct A-ring 1,7-enyne fragments have been developed, leading to the synthesis of numerous biologically interesting vitamin D3 derivatives, differing in both stereochemistry and substituents in the A-ring portion of 1α,25-dihydroxyvitamin D3. In this review, synthetic methods of A-ring 1,7-enyne synthons, including modifications at the 1-, 2-, 3- and 4-positions of the vitamin D A-ring system, will be fully introduced.

Keywords: 1α,25-dihydroxyvitamin D3, vitamin D, A-ring precursors, 1,7-enyne, synthon, palladium, coupling, synthesis, chemistry, homeostasis