- A Short, Efficient Copper-Mediated Synthesis of 1α,25-Dihydroxyvitamin D2 (1α,25-Dihydroxyergocalciferol) and C-24 Analogs
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Two synthetic routes to the nonnatural hormone 1α,25-dihydroxyergocalciferol [2b, 1α,25-(OH)2D2] and analogs modified at C-24 have been developed both starting from aldehyde 7b. Key steps in route A (eight steps, ≈38% overall yield f
- Torneiro, Mercedes,Fall, Yagamare,Castedo, Luis,Mouri?o, Antonio
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p. 6344 - 6352
(2007/10/03)
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- Process for the preparation of 1α,25-dihydroxyvitamin D2 and the 24-epimer thereof
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(22E)-5,7,22-Ergostatriene-1α,3β,25-triol and the 24-epimer thereof which are new intermediates for the synthesis of 1α,25-dihydroxyvitamin D2 and the 24-epimer thereof. A new process for the preparation of 1α,25-dihydroxyvitamin D2
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- Immunosuppressive agents
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The invention relates to pharmaceutical compositions comprising at least one Vitamin D derivative and a method of using the pharmaceutical compositions in suppressing immune responses.
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- 1,25-dihydroxyvitamin D2 compounds
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The invention is directed to the preparation of hydroxylated compounds of the vitamin D2 series and specifically to a process for synthesizing 1α,25-dihydroxyvitamin D2, 1β,25-dihydroxyvitamin D2, their corresponding 5,6-trans isomers and the C-24 epimers of these compounds. The hydroxylated vitamin D2 compounds obtained exhibit vitamin D-like activity and can be substituted for vitamin D3 or various of its known metabolites where such compounds are applied.
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- Stereocontrolled Total Synthesis of 1α,25-Dihydroxycholecalciferol and 1α,25-Dihydroxyergocalciferol
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1α,25-dihydroxycholecalciferol (4) and 1α,25-dihydroxyergocalciferol (7), the hormonally active forms of vitamin D3 (1) and vitamin D2 (5), were synthesized by a Horner-Wittig reaction of the phosphine oxide 11 with the ketones 10 and 12, respectively.The synthon 11 was obtained by a sequence that involves the stereospecific opening of epoxide 15, with sodium acetate in acetic acid, followed by oxidative degradation of the isopropenyl side chain and dehydration of the intermediate 22.Photoisomerisation of the resulting 23 gave 24, which was finally converted to 11.The hydroxylated ketone 10 was obtained from the known intermediate 28.The introduction of the 25-hydroxy side chain was achieved by reaction of the lithium derivative of 30 with the tosylate 29 to give 31, which was catalytically hydrogenated to 32 and then converted to 10.The ketone 12 was prepared by a stereocontrolled route that involves as the key step, the dipolar cycloaddition of nitrone 35 with methyl 3,3-dimethylacrylate (36) to give a 1:1 mixture of isoxazolidines 37 and 38.Stereochemical control was achieved by taking advantage of the thermal reversibility of the cycloaddition, which allows the reequilibration of undesired 37.Isoxazolidine 38 was readily transformed to 43 by reduction, followed by elimination of the nitrogen function, and finally oxidation to 12.
- Baggiolini, Enrico G.,Iacobelli, Jerome A.,Hennessy, Bernard M.,Batcho, Andrew D.,Sereno, John F.,Uskokovic, Milan R.
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p. 3098 - 3108
(2007/10/02)
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- Fluorovitamin D compounds and processes for their preparation
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Fluorine-substituted vitamin D compounds, methods for preparation of such compounds and fluorinated intermediate compounds used in such methods are disclosed. The fluorine-substituted vitamin D compounds are characterized by vitamin D-like activity in stimulating intestinal calcium transport and bone mobilization and in promoting the calcification of rachitic bone.
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