Enantioselective synthesis of optically pure (R)- and (S)-β-lysine via nitrone cycloaddition
作者:David Keirs、David Moffat、Karl Overton
DOI:10.1039/c39880000654
日期:——
Optically pure (R)- and (S)-β-lysines have been obtained via cycloaddition of chiral nitrone (4) to vinyl acetate, followed by facile chromatographic separation of the four resulting acetates (5) into two pairs of C-5 epimers and conversion of each pair into diastereoisomerically pure isoxazolidinone (7a or b).
The Synthesis of 4-Hydroxypipecolic Acids by Stereoselective Cycloaddition of Configurationally Stable Nitrones
作者:Franca M. Cordero、Simona Bonollo、Fabrizio Machetti、Alberto Brandi
DOI:10.1002/ejoc.200600104
日期:2006.7
diastereoselective synthesis of trans- and cis-4-hydroxypipecolic acids has been achieved with geometry-controlled nitrone cycloaddition chemistry. The cycloaddition of 3-butenol to enantiopure C-aminocarbonyl and C-alkoxycarbonyl nitrones having a definite (Z) and (E) configuration, respectively, occurs with complete regio- and exo selectivity. The acyclic (Z)-nitrone 12 affords two cycloadducts in a 1:1 ratio
Practical synthesis of both enantiomers of protected 4-oxopipecolic acid
作者:Fabrizio Machetti、Franca M Cordero、Francesco De Sarlo、Alberto Brandi
DOI:10.1016/s0040-4020(01)00429-x
日期:2001.6
A new synthesis of bothenantiomers of protected 4-oxopipecolic acid was achieved in six steps via 1,3-dipolar cycloaddition of C-ethoxycarbonyl N-(1R)-phenylethylnitrone to but-3-en-1-ol.