- PROCESS FOR THE PREPARATION OF [(1 S,2R)-3-[[(4-AMINOPHENYL)SULFONYL] (2-METHYLPROPYL)AMINO]-2-HYDROXY-1 -(PHENYLMETHYL)PROPYL]-CARBAMIC ACID (3R,3AS,6AR)HEXAHYDRO FURO[2,3-B]FURAN-3-YL ESTER AND ITS AMORPHOUS FORM
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The present invention relates to an improved process for the preparation of [(1 S,2R)-3-[ [(4-aminophenyl)sulfonyl] (2-methylpropyl)amino]-2-hydroxy- 1 -(phenylmethyl)propyl] - carbamic acid (3R,3aS,6aR)hexahydrofuro[2,3-b]furan-3-yl ester compound of formula- 1 represented by the following structural formula:
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Page/Page column 18-19
(2017/04/21)
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- Efficient asymmetric synthesis of (2R,3R)-3-{(1R)-1-[tert-Butyl(dimethyl)- siloxy]ethyl}-4-oxoazetidin-2-yl acetate
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(2R,3R)-3-{(1R)-1-[tert-Butyl(dimethyl)siloxy]ethyl}-4-oxoazetidin-2-yl acetate was efficiently prepared from l-ascorbic acid. The key steps were the a highly diastereoselective [2 + 2] cycloaddition of diketene with an (S)-glyceraldehyde-derived ald?imine to give the ketone, stereoselective titanium tetrachloride mediated asymmetric reduction to give the corrsponding S-configured alcohol, and Mitsunobu inversion of the latter to give the desired R-configured alcohol. Georg Thieme Verlag Stuttgart ? New York.
- Huang, Jian-Ping,Zhao, Lei,Gu, Shuang-Xi,Wang, Zhong-Hua,Zhang, Hao,Chen, Fen-Er,Dai, Hui-Fang
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experimental part
p. 555 - 562
(2011/04/15)
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- 1,4-Dioxane-2,5-dione-type monomers derived from l-ascorbic and d-isoascorbic acids. Synthesis and polymerisation
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l-Ascorbic and d-isoascorbic acids have been used as the starting materials for the preparation of (3R,4′S)-3-(2′,2′-dimethyl-1′,3′-dioxolan-4′-yl)-1,4-dioxane-2,5-dione (IPTA), (3R and S, 4′S,6R)-3-methyl-6-(2′,2′-dimethyl-1′,3′-dioxolan-4′-yl)-1,4-dioxane-2,5-dione (IPTP) and (3R,4′R)-3-(2′,2′-dimethyl-1′,3′-dioxolan-4′-yl)-1,4-dioxane-2,5-dione (IPEA), three novel 1,4-dioxane-2,5-dione-type monomers. Ring-opening homopolymerisation and copolymerisation of the IPTA monomer, derived from l-ascorbic acid, with d,l-lactide have been performed. The polymers were characterised by elemental microanalysis, as well as IR and 1H and 13C NMR spectroscopies. GPC was used to estimate product molecular weights, and thermal studies (DSC and TGA) revealed that all the polymers were amorphous, being stable up to 250 °C under nitrogen.
- Bueno, Manuel,Molina, Inmaculada,Galbis, Juan A.
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scheme or table
p. 2100 - 2104
(2010/01/18)
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- Enantiomeric synthesis of 3-amino-4-carbamoyloxymethyl-2-azetidonone-1-sulfate
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A novel enantiomeric synthesis from ascorbic acid of (3S,4S)-3-amino-4-carbamoyloxymethyl-2-azetidinone-1-sulfate, an intermediate for an antibiotic compound.
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