- An Enantioselective Approach to 4-O-Protected-2-cyclopentene-l,4-diol Derivatives via a Rhodium-Catalyzed Redox-Isomerization Reaction
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Kinetic resolution of a series of cyclopentene-1,4-diol derivatives has been successfully achieved with enantiomeric excess up to 99.4% and a kf/ks ratio of 55 by a rhodium-catalyzed redox-isomerization reaction in a noncoordinating solvent.
- Ren, Kai,Zhao, Mengmeng,Hu, Bei,Lu, Bin,Xie, Xiaomin,Ratovelomanana-Vidal, Virginie,Zhang, Zhaoguo
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p. 12572 - 12579
(2016/01/09)
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- A Novel Asymmetric Synthesis of Chiral Cyclopentanoid Building Blocks by the Use of Chiral Lithium Amide
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Enantioselective deprotonation of meso-epoxides, derived from 3-cyclopenten-1-ol, was examined using chiral lithium amide.Chiral cis-4-t-butyldimethylsiloxy-2-cyclopenten-1-ol, cis-4-tetrahydropyranyloxy-2-cyclopenten-1-ol, and their trans-isomers, which are useful chiral building blocks for the synthesis of cyclopentanoid natural compounds, were obtained with high enantiomeric excesses (72 - 90 percent ee).Both (R)- and (S)-4-hydroxy-2-cyclopenten-1-one were derived from (1S,4R)-4-t-butyldimethylsiloxy)-2-cyclopenten-1-ol stereospecifically.
- Asami, Masatoshi
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p. 1402 - 1408
(2007/10/02)
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- A PALLADIUM-CATALYZED ROUTE TO MONO- AND DIPROTECTED CIS-2-CYCLOPENTENE-1,4-DIOLS
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The ?-allylpalladium complex arising from cyclopentadiene monoepoxide has been shown to react with carboxylic acids and derivatives both as a nucleophile and an electrophile.This reaction represents an attractive synthetic route to protected versions of cis-2-cyclopentene-1,4-diol.
- Deardorff, Donald R.,Myles, David C.,MacFerrin, Kurtis D.
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p. 5615 - 5618
(2007/10/02)
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- SYN-1,4-ADDITION OF CARBOXYLATE SALTS TO CYCLIC ALLYLIC EPOXIDES MEDIATED BY CUPROUS CHLORIDE
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A mild method for the 1,4-syn opening of certain cyclic allylic epoxides has been found, using sodium carboxylates in the presence of cuprous chloride.
- Marino, J. P.,Jaen, Juan C.
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p. 441 - 444
(2007/10/02)
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- STEREOCHEMICAL STUDIES - LVII. SYNTHESIS OF OPTICALLY ACTIVE COMPOUNDS BY THE NOVEL USE OF MESO-COMPOUNDS -1. EFFICIENT SYNTHESIS OF TWO STRUCTURAL TYPES OF OPTICALLY PURE PROSTAGLANDIN INTERMEDIATES.
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With an aim to overcome several inefficient aspects of ordinary methods of preparing optically active compounds, we have developed a new method which recommends utilization of symmetrically functionalized meso-compounds in place of racemic compounds.As shown in Scheme 1, when the meso-compound (I) is monofunctionalized by an optically active functional group (A) and each of the formed diastereomers (II and III) is subjected to further chemical elaborations including protective group transposition, it is theoretically possible to convert the total amount of the starting material (I) into the requisite optically pure product (VI or VII) by selecting synthetic schemes.By employing this novel concept, two structural types of the prostaglandin intermediates ((-)- and (+)-2a,b) have been prepared from the meso-diols (1a,b) by way of the two diastereomeric monoesters (13a,b and 14a,b) which are produced by the reactions 1a,b with N-mesyl- and N-phthaloyl-(S)-phenylalanyl chloride (3a,b).
- Nara, M,Terashima, S.,Yamada, S.
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p. 3161 - 3170
(2007/10/02)
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