Expeditious stereoselective synthesis of L-iminosugars precursors via a Mitsunobu reaction
Résumé
An efficient stereoselective synthesis of l-imino-C-gulosides is disclosed. Starting from the 2,3:4,6-di-O-isopropylidene-d-mannopyranose the synthetic pathway involves first a Wittig reaction with CMPP to introduce the carbon at the pseudo-anomeric position, followed by a Michael reaction under ultrasound activation to introduce the nitrogen center, and finally a Mitsunobu reaction for the ring closure leading to the C-iminosugar from the l-series