(1R, 2R)-2-nitroxycyclohexan-1-ol : First example of a cyclohexyl based chiral auxiliary with nitroxy function as diastereoface discriminating group
摘要:
Application of nitroxy substituent as diastereoface discriminating group in a cyclohexyl based chiral auxiliary has been described. Copyright (C) 1996 Elsevier Science Ltd
Catalytic Asymmetric Synthesis of Dihydrofurans and Cyclopentenols with Tertiary Stereocenters
作者:Zhongtao Wu、Ashoka V. R. Madduri、Syuzanna R. Harutyunyan、Adriaan J. Minnaard
DOI:10.1002/ejoc.201301476
日期:2014.1
2-addition of Grignard reagents to enones in combination with Sonogashira coupling/cyclization or ring-closing metathesis. By this approach, dihydrofurans with an oxygen-containing tertiarystereocenter and chiral tertiary cyclopentenols are efficiently prepared. The absolute stereochemistry of the products has been established.
Synthese D'α-hydroxyacides optiquement actifs par addition d'organozinciques sur le phenylglyoxalate de (−) menthyle
作者:G. Boireau、A. Deberly、D. Abenhaïm
DOI:10.1016/s0040-4020(01)89110-9
日期:1989.1
organozinciques obtenus par échange in situ entre un réactif de Grignard et une solution de ZnCl2 ou ZnBr2 dans le diéthyléther ou le THF, s'additionnent sélectivement au carbonyle du phénylglyoxalate de (−) menthyle. Une variété d'acides mandéliques α-substitués deconfigurationsabsolues connues sont ainsi obtenus avec de bons rendements et, dans la marjorité des cas, une bonne induction asymétrique.
Enantioselective synthesis of α- and β-hydroxy acids using -2-phenylcyclohexan-1-ol-as chiral auxiliary
作者:D. Basavaiah、T.K. Bharathi
DOI:10.1016/s0040-4039(00)92724-2
日期:1991.7
-2-Phenylcyclohexanol has been used as a chiral auxiliary for the preparation of α- and β-hydroxyacids in 85–100% and 11–89% enantiomeric purities respectively.
Isomannide and isosorbide as new chiral auxiliaries for the stereoselective synthesis of tertiary α-hydroxy acids
作者:André Loupy、Daphné A Monteux
DOI:10.1016/s0040-4020(02)00024-8
日期:2002.2
isosorbide are selectively protected to provide new chiralauxiliaries suitable for the preparation of enantiopure tertiary α-hydroxyacids. Diastereoselective additions of organozinc reagents on the derived phenylglyoxylates afford the desired α-hydroxyacids with 60–99% ee after saponification. Both absolute configurations of the α-hydroxyacids can be accessed, by adapted choice of either the starting
New cyclohexyl-based chiral auxiliaries: Enantioselective synthesis of α-hydroxy acids
作者:Deevi Basavaiah、Peddinti Rama Krishna
DOI:10.1016/0040-4020(95)00771-y
日期:1995.10
2R)-2-(4-tert-Butylphenoxy)cyclohexan-1-ol (5) and (1R,2R)-2-(4-phenylphenoxy)cyclohexan-1-ol (6) have been used for the first time as chiralauxiliaries. Addition of alkylzinc chlorides to the corresponding glyoxylates 5a, 6a, after hydrolysis, provided (R)-α-hydroxy acids in high optical purities.