Molecular Complexity by Organocatalytic One-Pot Strategies

Significance

The authors report enantio- and ­diastereoselective one-pot procedures to 4,5-di­substituted isoxazoline N-oxides having up to three contiguous stereocenters. The cascade ­reaction consists of an enantioselective, organocatalytic functionalization to α-bromo aldehydes or α,β-epoxy aldehydes, followed by a base mediated face-selective Henry reaction, and a subsequent stereospecific intramolecular O-alkylation. The obtained 4,5-disubstituted isoxazoline N-oxides are converted into l-ribo-phytosphingosine and polyhydroxylated α-amino acids.