Kinetic resolution and parallel kinetic resolution of methyl (±)-5-alkyl-cyclopentene-1-carboxylates for the asymmetric synthesis of 5-alkyl-cispentacin derivatives

被引：57

作者：

Davies, SG ^{[1
]}

Garner, AC ^{[1
]}

Long, MJC ^{[1
]}

Morrison, RM ^{[1
]}

Roberts, PM ^{[1
]}

Savory, ED ^{[1
]}

Smith, AD ^{[1
]}

Sweet, MJ ^{[1
]}

Withey, JM ^{[1
]}

机构：

[1] Univ Oxford, Dept Organ Chem, Chem Res Lab, Oxford OX1 3TA, England

来源：

ORGANIC & BIOMOLECULAR CHEMISTRY | 2005年 / 3卷 / 15期

关键词：

D O I：

10.1039/b506339f

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

Conjugate addition of lithium dibenzylamide to methyl 5-isopropyl, 5-phenyl- and 5-tert-butyl-cyclopentene-1-carboxylates occurs with high levels of substrate control (> 88% de), with preferential addition to the face of the cyclic alpha,beta-unsaturated acceptor anti- to the stereodirecting 5-alkyl substituent. Treatment of a range of methyl (+/-)-5-alkyl-cyclopentene-1-carboxylates with both lithium (+/-)-N-benzyl-N-alpha-methylbenzylamide and lithium (+/-)-N-3,4-dimethoxybenzyl-N-alpha-methylbenzylamide indicates signi. cant enantiorecognition in their mutual kinetic resolutions, with preferential addition anti- to the 5-alkyl substituent, giving the 1,2-syn-1,5-anti-arrangement (E > 16) after enolate protonation anti- to the amino functionality. The kinetic resolution of a range of methyl (+/-)-5-alkyl-cyclopentene-1-carboxylates with lithium (S)-N-benzyl-N-alpha-methylbenzylamide, and their efficient parallel kinetic resolution with a pseudoenantiomeric mixture of lithium (S)-N-benzyl-N-alpha-methylbenzylamide and lithium (R)-N-3,4-dimethoxybenzyl-N-alpha-methylbenzylamide are also demonstrated, giving a range of 5-alkyl-cispentacin derivatives in > 98% de and high ee after N-deprotection.

引用

页码：2762 / 2775

页数：14

共 53 条

[1] The use of enantiomerically pure ketene dithioacetal bis(sulfoxides) in highly diastereoselective intramolecular nitrone cycloadditions.: Application in the total synthesis of the β-amino acid (-)-cispentacin and the first asymmetric synthesis of cis-(3R,4R)-4-amino-pyrrolidine-3-carboxylic acid [J].

Aggarwal, VK ;

Roseblade, S ;

Alexander, R .

ORGANIC & BIOMOLECULAR CHEMISTRY, 2003, 1 (04) :684-691

[2] Highly diastereoselective nitrone cycloaddition onto a chiral ketene equivalent: Asymmetric synthesis of cispentacin [J].

Aggarwal, VK ;

Roseblade, SJ ;

Barrell, JK ;

Alexander, R .

ORGANIC LETTERS, 2002, 4 (07) :1227-1229

[3] Parallel kinetic resolution of racemic amines using 3-N,N-diacylaminoquinazolin-4(3H)-ones [J].

Al-Sehemi, AG ;

Atkinson, RS ;

Meades, CK .

CHEMICAL COMMUNICATIONS, 2001, (24) :2684-2685

[4] METAL-AMIDES IN ORGANIC-SYNTHESIS .7. STEREODIVERGENT SYNTHESIS OF THE ENOLATES OF A BETA-AMINO ESTER BY USING LITHIUM N-BENZYLTRIMETHYLSILYLAMIDE [J].

ASAO, N ;

UYEHARA, T ;

YAMAMOTO, Y .

TETRAHEDRON, 1990, 46 (13-14) :4563-4572

[5] Asymmetric synthesis of (1R,2S,3R)-γ-methyl-cis-pentacin by a kinetic resolution protocol [J].

Bailey, S ;

Davies, SG ;

Smith, AD ;

Withey, JM .

CHEMICAL COMMUNICATIONS, 2002, (23) :2910-2911

[6] Protecting group controlled stereoselective alkylation of asymmetrized bis(hydroxymethyl)propanoates (BHYMP*) [J].

Banfi, L ;

Guanti, G .

TETRAHEDRON-ASYMMETRY, 1999, 10 (03) :439-447

[7]

Bertozzi F, 2001, ANGEW CHEM INT EDIT, V40, P930, DOI 10.1002/1521-3773(20010302)40:5<930::AID-ANIE930>3.0.CO

[8]

2-7

[9] An alkaloid-mediated desymmetrization of meso-anhydrides via a nucleophilic ring opening with benzyl alcohol and its application in the synthesis of highly enantiomerically enriched β-amino acids [J].

Bolm, C ;

Schiffers, I ;

Atodiresei, I ;

Hackenberger, CPR .

TETRAHEDRON-ASYMMETRY, 2003, 14 (22) :3455-3467

[10]

Bolm C, 2001, SYNTHESIS-STUTTGART, P1719

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