Stereocontrolled addition of Grignard reagents to α-alkoxy nitrones. Synthesis of syn and anti 3-amino-1,2-diols
摘要:
The stereoselective addition of Grignard reagents to alpha-alkoxy nitrones has been achieved with excellent stereocontrol using ZnBr2 and Et2AlCl as precomplexing agents to obtain the corresponding syn- and anti- adducts, respectively. The obtained hydroxylamines have been transformed into valuable 3-amino-1,2-diols. (C) 1997 Elsevier Science Ltd.
Stereocontrolled addition of Grignard reagents to α-alkoxy nitrones. Synthesis of syn and anti 3-amino-1,2-diols
摘要:
The stereoselective addition of Grignard reagents to alpha-alkoxy nitrones has been achieved with excellent stereocontrol using ZnBr2 and Et2AlCl as precomplexing agents to obtain the corresponding syn- and anti- adducts, respectively. The obtained hydroxylamines have been transformed into valuable 3-amino-1,2-diols. (C) 1997 Elsevier Science Ltd.
Nucleophilic additions of Grignard reagents to N-benzyl-2,3-O-isopropylidene-D-glyceraldehyde nitrone (BIGN). Synthesis of (2S,3R) and (2S,3S)-3-phenylisoserine
作者:Pedro Merino、Elena Castillo、Santiago Franco、Francisco L. Merchán、Tomas Tejero
DOI:10.1016/s0040-4020(98)00741-8
日期:1998.10
A remarkable Lewis acid tuning has been observed in the nucleophilic addition of Grignard reagent to BIGN, the N-benzyl nitrone derived from 1,2-O-isopropylidene-D-glyceraldehyde. The obtained alpha,beta-dialkoxy hydroxylamines can serve as starting points for the synthesis of both aminodiols and alpha-hydroxy-beta-amino acids. This synthetic approach is illustrated by the synthesis of the antipode of the C-13 side chain of Taxotere as well as its C-3 epimer. (C) 1998 Elsevier Science Ltd. All rights reserved.