- Asymmetric synthesis of (-)-tetrahydrolipstatin from a β-hydroxy- δ-oxo sulfoxide
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An asymmetric synthesis of (-)-tetrahydrolipstatin is described. A palladium-catalyzed regioselective oxidation of an alkene to a ketone, highly diastereoselective reduction of a β-hydroxy ketone, selective oxidation of a diol, and modular synthesis are the key features of the synthesis. Georg Thieme Verlag Stuttgart.
- Raghavan, Sadagopan,Rathore, Kailash
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scheme or table
p. 1285 - 1288
(2009/12/01)
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- Asymmetric synthesis of (-)-tetrahydrolipstatin
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Attempts toward the asymmetric synthesis of (-)-tetrahydrolipstatin are described. A palladium catalyzed Wacker-type reaction to convert an alkene to a ketone, highly diastereoselective reduction of a β-hydroxy ketone, selective oxidation of a diol, and modular synthesis are the key features of the successful approach.
- Raghavan, Sadagopan,Rathore, Kailash
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experimental part
p. 10083 - 10092
(2010/02/27)
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- Asymmetric synthesis of tetrahydrolipstatin and valilactone
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The highly diastereoselective aldol reaction between acyl complexes of the iron chiral auxiliary [(η5-C5H5)Fe(CO)(PPh3)] and β-hydroxy aldehydes (obtained via a Noyori asymmetric hydrogenation), followed by a tandem oxidative decomplexation-cyclisation process gives access to β-substituted and α,β-disubstituted β-lactones in high ee. This methodology has been employed in the asymmetric syntheses of tetrahydrolipstatin and valilactone.
- Case-Green, Stephen C.,Davies, Stephen G.,Roberts, Paul M.,Russell, Angela J.,Thomson, James E.
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experimental part
p. 2620 - 2631
(2009/04/06)
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- Enantioselective total synthesis of (-)-tetrahydrolipstatin using Oppolzer's sultam directed aldol reaction
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A highly practical and concise stereoselective total synthesis of (-)-tetrahydrolipstatin is achieved using Oppolzer's sultam directed aldol reaction as the key step.
- Kumaraswamy,Markondaiah
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p. 327 - 330
(2008/09/17)
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- Stereocontrol in organic synthesis using silicon-containing compounds. A synthesis of (-)-tetrahydrolipstatin using the alkylation of a β-silyl ester and the hydroboration of an allylsilane
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Conjugate addition of bis(Z-tridec-1-enyl)cuprate Z-10 to (5S)-1-[(Z)-3′-dimethyl(phenyl)silylprop-2-enoyl]-5-(trityloxymethyl) pyrrolidin-2-one Z-6 gave the 3A-imide Z-12. Subsequent enolate n-hexylation of the benzyl ester Z-13a derived from this imide gave the 2R,3S-ester Z-14a. Reduction of the ester group and protection of the alcohol as its TBDMS group gave the allylsilane (Z)(7 R,8S)-7-(tert-butyldimethylsilyloxymethyl)-8-dimethyl(phenyl)silylhenicos-9-ene Z-15. Hydroboration-oxidation gave the 7R,8S,10S-alcohol 16. Protection of the C-10 hydroxy as its benzyl ether, removal of the silyl protecting group and oxidation gave (2R,3S,5S)-5-benzyloxy-3-dimethyl(phenyl)silyl-2-hexylhexadecanoic acid 19. Silyl-to-hydroxy conversion, β-lactone formation, and hydrogenolysis gave the known alcohol (3S,4S)-3-hexyl-4-[(S)-2′-hydroxytridecyl]oxetan-2-one 22, from which tetrahydrolipstatin 1 was prepared by a conventional esterification. Each of the stereochemistry determining steps, 4 → Z-6, 7 → E-8, E-8 → Z-9, Z-6 + Z-10 → Z-12, Z-13a → Z-14a and Z-15 → 16, took place with a remarkably high level of open-chain stereocontrol.
- Fleming, Ian,Lawrence, Nicholas J.
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p. 2679 - 2686
(2007/10/03)
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- Synthesis of Tetrahydrolipstatin
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An asymmetric synthesis of tetrahydrolipstati (4) is described.Application of our previously described in situ cyclopentadiene alkylation-asymmetric hydroboration protocol provided the key chiral alcohol 9.In the course of this work, the presence of a free hydroxyl group was found to exert a strong directing effect on the regioselectivity of a Baeyer-Villiger reaction (16 --> 17).Subsequent transformations of lactone 17 produced tetrahydrolipstatin.
- Chadha, N. K.,Batcho, A. D.,Tang, P. C.,Courtney, L. F.,Cook, C. M.,et al.
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p. 4714 - 4718
(2007/10/02)
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