- Enantiomeric impurity PY2 of tacalcitol and preparation method and application thereof
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The invention discloses an enantiomeric impurity PY2 of tacalcitol, i.e., (1 alpha, 3 beta, 5Z, 7E, 24S)-9,10-Secocholesta-5,7,10(19)-triene-1,3,24-triol, and a preparation method thereof, and belongsto the technical field of chemical pharmaceutical. The high-purity relevant impurity PY2 of the tacalcitol, which is disclosed by the invention, can be used as an impurity standard substance in the tacalcitol finished product detection analysis so as to promote accurate positioning and nature determination of the tacalcitol finished product detection analysis on the impurity and benefit reinforcement of control on the impurity, thereby improving quality of a tacalcitol finished product. The method provided by the invention has the advantages that the raw materials are cheap and easy to obtain, the operation is simple, the reproducibility is good in and the HPLC (High Performance Liquid Chromatography) purity is greater than or equal to 99.5%.
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- Synthesis of 24(28)-methylene-1α-hydroxyvitamin D3, a novel vitamin D3 analogue
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24(28)-Methylene-1α-hydroxyvitamin D3 was synthesised in 13 steps from vitamin D2. The key step of the synthesis involved the Wittig-Horner olefination of a nor-vitamin D2 aldehyde with diethylphosphono-3-methyl-2-butanone
- Guo, Wei,Fang, Zhijie,Li, Hongliang,Liu, Yanan
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p. 231 - 235
(2014/05/06)
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- Synthesis and biological evaluation of a new vitamin D2 analogue
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A new vitamin D2 analogue was synthesized using the Julia-Kocienski olefination. It has antiproliferative effects on cell lines from squamous cell carcinomas of colon and head and neck, but is also as hypercalcaemic as calcitriol in vivo.
- Gandara, Zoila,Perez, Manuel,Salomon, Debora G.,Ferronato, Maria J.,Fermento, Maria E.,Curino, Alejandro C.,Facchinetti, Maria M.,Gomez, Generosa,Fall, Yagamare
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p. 6276 - 6279
(2012/10/30)
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- Stereoselective synthesis of (22Z)-25-hydroxyvitamin D2 and (22Z)-1α,25-dihydroxyvitamin D2
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Two new vitamin D2 analogues, (22Z)-25-(OH)-D2 and (22Z)-1α,25-(OH)2-D2, were serendipitously synthesized from vitamin D2 and using the Julia-Kocienski olefination.
- Gándara, Zoila,Pérez, Manuel,Pérez-García, Xenxo,Gómez, Generosa,Fall, Yagamare
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scheme or table
p. 4874 - 4877
(2009/11/30)
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- Synthesis of a Biologically Active Vitamine-D2 Metabolite
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The synthesis of 1α,25,28-trihydroxyvitamin-D2 (1) from vitamin-D2 is described.Approaches to the upper side-chain synthon via the chiral sulfone 15, prepared either through the enzymatic resolution of 10 or the opening of the optica
- Choudhry, Satish C.,Belica, Peter S.,Coffen, David L.,Focella, Antonino,Maehr, Hubert,et al.
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p. 1496 - 1500
(2007/10/02)
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- HOMOLYTIC AZIRIDINE OPENING (AZA VARIANT OF CYCLOPROPYLCARBINYL-HOMOALLYL REARRANGEMENT) BY ADDITION OF TRIBUTYLTIN RADICAL TO N-ACYLAZIRIDINES. FACTORS CONTRIBUTING TO THE REGIOSELECTIVITY
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AIBN initiated reaction of N-acylaziridines 1 with Bu3SnH in refluxing benzene provided products 5 and 8 of reductive ring opening.Yields (practically quantitative in most cases) fell drastically with steric hindrance of the addition of Bu3Sn to the acyl oxygen of 1.They depended to some extent on the experimental conditions for hydrogen capturing when aziridine homolysis provided a primary radical 3 or 6.The regioselectivity of (probably reversible) ring homolysis can be understood in terms of the stability of the arising radical (3, 6), of stereoelectronic control (e.g. 1i as compared to 1h) and of frontier orbital interactions (1j).A possible difference in bond lengths as explanation for the formation of the primary radical from 1j did not find support from an X-ray structure analysis of N-tosyl-2-methyl-aziridine 11.Isomeric products were obtained only twice (1i, 1j) with a dependence of the ratio 5j:8j on concentration and hydrogen isotope of Bu3SnH.No such dependence was found for the ratio 5:14 (reduction without and with an intervening cyclization of 3 leading to a pyrrolidone) obtained from the N-cinnamoylaziridine 1l.This ratio (1:9 for 1l and 1:3 for 1n) must reflect the E-Z isomers in 3.The observed preference for the formation of E-3 from 2 can be explained by stereoelectronic and steric effects.A cinnamoyl double bond in 5 was saturated depending on experimental conditions.
- Werry, Juergen,Stamm, Helmut,Lin, Pen-Yuan,Falkenstein, Reinhard,Gries, Stefan,Irngartinger, Hermann
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p. 5015 - 5028
(2007/10/02)
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