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
摘要:
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.
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.
Magnesium chloride (MgCl2) catalyzed highly regioselective C-3 ring opening of 2,3 epoxy alcohols by N-nucleophile
作者:Amit Kumar、Gautam Panda
DOI:10.1016/j.tetlet.2021.153013
日期:2021.4
herein report Magnesiumchloride (MgCl2) catalyzed first highly C3-selective ring-opening reaction of various 2,3-epoxy alcohols with assorted N-Nucleophiles and sodium azide to furnish 3-amino-1,2 diols and 3-azido-1,2 diols respectively in high yields under mild reactionconditions. This protocol attributes the use of catalytic amount of Magnesiumchloride (MgCl2), simple reactionconditions, practical