The asymmetric synthesis of β-aryl-α-hydroxy esters from β-aryl-α,β-dihydroxy esters
摘要:
alpha,beta-Dihydroxy-beta-aryl esters obtained via Sharpless asymmetric dihydroxylation (AD) of substituted cinnamate esters are reduced by sequential reaction with trimethyl orthoacetate and acetyl bromide followed by catalytic hydrogenolysis in methanol to give enantiomerically enriched beta-aryl-alpha-hydroxy esters. (C) 2002 Elsevier Science Ltd. All rights reserved.
The asymmetric synthesis of β-aryl-α-hydroxy esters from β-aryl-α,β-dihydroxy esters
摘要:
alpha,beta-Dihydroxy-beta-aryl esters obtained via Sharpless asymmetric dihydroxylation (AD) of substituted cinnamate esters are reduced by sequential reaction with trimethyl orthoacetate and acetyl bromide followed by catalytic hydrogenolysis in methanol to give enantiomerically enriched beta-aryl-alpha-hydroxy esters. (C) 2002 Elsevier Science Ltd. All rights reserved.
Lipase-catalyzed transesterification as a practical route to homochiral syn-1,2-diols. The synthesis of the taxol side chain
作者:Donghyun Lee、Mahn-Joo Kim
DOI:10.1016/s0040-4039(98)00147-6
日期:1998.4
syn-2,3-Dihydoxy-3-phenyl-propanoic acid methyl ester (1a) and its simple derivatives (1b-e) are efficiently resolved in LPS-catalyzed transesterification, leading to the synthesis of the taxolsidechain and analogs from both resolved enantiomers.
syn -2,3-二羟基-3-苯基丙酸甲酯(1a)及其简单衍生物(1b-e)在LPS催化的酯交换反应中得到有效拆分,从而导致紫杉醇侧链及其类似物的合成拆分的对映体。
Improved large-scale synthesis of phenylisoserine and the taxol C-13 side chain
作者:Michael V Voronkov、Alexander V Gontcharov、Zhi-Min Wang
DOI:10.1016/s0040-4039(02)02434-6
日期:2003.1
Dihydrodihydroxycinnamic acids and their esters react with acetonitrile or benzonitrile in the presence of sulfuric acid to afford the corresponding syn-β-amino-α-hydroxypropionic acid derivatives. High yields and diastereoselectivity of this transformation allows preparation of various phenylisoserine derivatives on a practical scale.
A Strategy for the Asymmetric Aminohomologation of α,β-Dihydroxy Aldehydes: Application to the Synthesis of the Southwest Tripeptide Segment of Echinocandin B
作者:Claudio Palomo、Mikel Oiarbide、Aitor Landa
DOI:10.1021/jo990964c
日期:2000.1.1
The synthesis of the (2S,3S,4S)-3,4-dihydroxyhomotyrosine amino acid segment, present in echinocandin B, in its activated form ready for peptide coupling is described. The key steps of the approach are the enantioselective AD reaction of 4-methoxycinnamic acid methyl ester, a completely diastereoselective [2 + 2] hydroxyketene-imine cycloaddition, and the TEMPO-assisted cyclo-expansion of the resulting 3-hydroxy beta-lactam to the corresponding alpha-amino acid N-carboxy anhydride (NCA). The smooth opening of the latter upon treatment with L-Thr((OSiBuPh2)-Bu-t)OMe and further acylation with the N-Cbz protected L-4-tert-butyldiphenylsilyloxy proline rendered the southwest portion of echinocandin B.
The asymmetric synthesis of β-aryl-α-hydroxy esters from β-aryl-α,β-dihydroxy esters
作者:Nicholas J Lawrence、Stephen Brown
DOI:10.1016/s0040-4020(01)01176-0
日期:2002.1
alpha,beta-Dihydroxy-beta-aryl esters obtained via Sharpless asymmetric dihydroxylation (AD) of substituted cinnamate esters are reduced by sequential reaction with trimethyl orthoacetate and acetyl bromide followed by catalytic hydrogenolysis in methanol to give enantiomerically enriched beta-aryl-alpha-hydroxy esters. (C) 2002 Elsevier Science Ltd. All rights reserved.