- Secondary compounds in the catalytic hydrogenation of enone and allylic alcohol prostaglandin intermediates: Isolation, characterization, and X-ray crystallography
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The discovery of the intraocular pressure reduction of 13,14-hydrogenated prostaglandins, among which Latanoprost is the most used drug in glaucoma treatment, has stimulated researchers to improve the synthesis of prostaglandins and their structural analo
- Tǎnase, Constantin I.,Cocu, Florea,Drǎghici, Constantin,Hanganu, Anamaria,Pintilie, Lucia,Maganu, Maria,Munteanu, Cristian V. A.,Shova, Sergiu
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p. 7582 - 7599
(2019/05/27)
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- Reduction of prostaglandin unsaturated ketones to secondary allylic alcohols by hydrogen transfer over mesoporous-supported PtSn catalysts
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Supported PtSn catalysts were prepared by successive impregnation of SiO2, MCM-41, or MCM-48 materials with Sn and Pt, followed by calcination and reduction. The characteristics of the bimetallic catalysts were related to the catalytic behavior in the hydrogen transfer reduction of the unsaturated ketone moiety of the prostaglandin lactonic enone intermediate ([3aα,4α(E),5β6aα]-(±)-4-[4-(3- chlorophenoxy)-3-oxo-1-butenyl]-hexahydro-5-hydroxy-2H-cyclop enta[b]-furan-2-one. Isopropanol was utilized as the reductant. High chemoselectivities to the allylic alcohol were realized with catalysts containing 5 wt % Pt and 5-10 wt % Sn on MCM-41 or MCM-48. Characterization of these optimum catalysts revealed that most of the Pt and part of the Sn formed supported alloy particles with PtSn and PtSn2 composition; the rest of the Sn was presented as dispersed Sn2+/4+. Activation of the carbonyl group on oxidized Sn, steric shielding of the C=C bond by bulky substituents, and use of the hydrogen transfer donor seemed crucial for obtaining high allylic alcohol chemoselectivities. In some cases, the mesoporous texture of the support induced considerably diastereoselectivity, with one isomer of the secondary allylic alcohol prevailing over its epimer.
- Jacobs,Coman,De Bruyn,Parvulescu,De Vos
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p. 218 - 229
(2007/10/03)
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