Protecting group directed diversity during Mitsunobu cyclization of a carbohydrate derived diamino triol. Synthesis of novel bridged bicyclic and six-membered iminocyclitolsElectronic supplementary information (ESI) available: Copies of 1H and 13C NMR spectra of all new compounds are provided. CCDC 881845 and 881846. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c2ob27000e

• Main Authors: Ganesan, Muthupandian, Salunke, Rahul Vilas, Singh, Nem, Ramesh, Namakkal G
• Format: Article
• Language: English
• ISSN: 1477-0520; 1477-0539
• DOI: 10.1039/c2ob27000e

A novel protecting group directed diversity leading to the synthesis of bridged bicyclic and six-membered iminocyclitols from a common carbohydrate derived diamino triol under Mitsunobu conditions is reported. When the intramolecular cyclization of benzoyl derivative 16 was carried out under Mitsunobu conditions, an unprecedented one-pot domino intramolecular "cyclization- N → O benzoyl migration-cyclization" reaction sequence occurred resulting in the formation of a chiral 2,6-diazabicyclo[3.2.1]octane-4,8-diol 21 in high yield. The structure of this novel bridged bicyclic compound was established through detailed NMR studies and single crystal X-ray analysis. On the other hand, the tert -butyldimethylsilyl derivative of the same substrate afforded protected 6-amino-1,6-dideoxy- l -gulonojirimycin 32 as the sole product under identical conditions. An attempt has been made to explain this difference in their reactivity through conformational analysis. The glycosidase inhibition studies of new compounds reported in this manuscript revealed that these molecules display moderate but selective inhibition against β- N -acetylhexosaminidase. A novel and an unprecedented protecting group directed diversity leading to the synthesis of bridged bicyclic and six-membered iminocyclitols from a common carbohydrate derived diamino triol under Mitsunobu conditions is reported.