… nitrone cycloadditions. Application in the total synthesis of the β-amino acid (−)-cispentacin and the first asymmetric synthesis of cis-(3R, 4R)-4-amino-pyrrolidine-3- …
Intramolecular 1, 3-dipolar nitrone cycloaddition onto an enantiomerically pure ketene dithioacetal dioxide using a three-carbon tether gave the corresponding 5, 5-disubstituted isoxazolidine as a single diastereomer in good yield. This reaction has been used as the key step in an asymmetric synthesis of the naturally occurring antibiotic,(−)-cispentacin. An asymmetric synthesis of 4-amino-pyrrolidine-3-carboxylic acid has also been carried out ...
