Catalytic asymmetric synthesis and anticancer effects of the novel non-calcemic analog of vitamin D, 2α-fluoro-19-nor-22-oxa-1α,25-dihydroxyvitamin D 3 in metastatic lung carcinoma

Abstract

1α,25-Dihydroxyvitamin D 3 (1α,25-D 3) has potent antiproliferative and anti-invasive properties in vitro in cancer cells. However, the major limitation to its clinical use is that it causes hypercalcemia. Therefore, vitamin D analogs with potent cell regulatory effects but with weaker calcemic effects than 1α,25-D 3 are required. Among them, 22-oxa-1α,25-D 3 and 19-nor-1α,25-D 3 have anti-cancer effects with relatively low calcemic effects. Modifications at the C-2α position of the A-ring also produced analogs with a unique biological profile. Not only the side-chain but also the A-ring modification thus generates a unique analog with potent cell regulatory effects and low calcemic activity as well. We report here that the hybrid 1α,25-D 3 analog, synthesized via the highly regio- and stereo-selective ring opening 2α-fluorination and catalytic asymmetric carbonyl-ene cyclization, with 2α-fluoro, 19-nor, and 22-oxa modification exhibits unique cell regulatory activities against the development of metastatic lung carcinoma.