O-alkylation versus C-alkylation under mitsunobu conditions

Véronique Barragan-Montero (1) , Loic Toupet (2) , Catalina Gurgui (1) , Lycia Uttaro (1) , Alain Fruchier

1 IBMM - Institut des Biomolécules Max Mousseron [Pôle Chimie Balard]
2 GMCM - Groupe matière condensée et matériaux

A comparative study of the Mitsunobu reaction at C1 and C6 positions of mannose using bis(2,2,2-trifluoroethyl) malonate as nucleophile is disclosed. While C-alkylation was predominant at the C6 position, only O-alkylation occurred at the anomeric position of the carbohydrate. Some factors playing a role in the selectivity of the reaction are discussed and an inverse mechanism of the Mitsunobu reaction for the anomeric position is proposed.

Domaines: Chimie organique

Véronique Barragan-Montero, Loic Toupet, Catalina Gurgui, Lycia Uttaro, Alain Fruchier. O-alkylation versus C-alkylation under mitsunobu conditions. Tetrahedron, 2007, 63, pp.9345-9353. ⟨10.1016/j.tet.2007.07.002⟩. ⟨hal-00356317⟩