Improved and efficient synthesis of Maxacalcitol

Maxacalcitol, the 22-oxa-derivative of 1α, 25-dihydroxyvitamin D3, has been used as an antihyperparathyroidism and antipsoriatic drug. In this paper, an alternative synthetic route has been developed using commercially available vitamin D2 as the starting material. In addition, as a key intermediate, the asymmetric synthesis of 20(S)-alcohol 14 with the chiral auxiliary (R-CBS) was described for the first time. This new synthetic route afforded Maxacalcitol with improved overall yield (13.9%) in eleven steps.

Graphical abstractIn this paper, an alternative synthetic route has been developed using commercially available vitamin D2 as the starting material for the synthesis of Maxacalcitol. In addition, as a key intermediate, the asymmetric synthesis of 20(S)-alcohol 14 with the chiral auxiliary (R-CBS) was described for the first time.Figure optionsDownload full-size imageDownload as PowerPoint slide