A New Synthesis of Polyhydroxylated Cyclopentane β-Amino Acids from Nitro Sugars

A ne stereocontrolled nitro sugar-mediated synthesis of polyhydroxylated β-amino acids is reported. The key step of this approach is a Michael addition of the lithium salt of tris(phenylthio)methane (a carboxyl synthetic equivalent) to sugar nitro olefins. This is followed by the generation of the amino acid functionality by the transformation of the tris(phenylthio)methyl substituent into the carboxylic acid functionality and the reduction of the nitro group to an amino group.