Samarium Diiodide Mediated Coupling of 2-Pyridylsulfonyl Furanosides with Aldehydes and Ketones: A General Synthesis of C-Furanosides

Diiodosamarium-mediated coupling of anomeric 2-pyridyl sulfones derived from furanosides with carbonyl compounds, aldehydes, and ketones gave -hydroxylated 2,5-trans-dialkylated tetrahydrofurans with good yields and useful stereoselectivities. The main control element of the reaction is the substituent on the 4-position or the starting furanosyl sulfone. C-Furanosides of D-arabinose and of D-ribose were obtained from sulfones prepared from the corresponding furanosides. Finally, a di-C-arabinofuranoside, a C-disaccharide analogue of a major motif of the arabinogalactan from the mycobacterial cell wall, was prepared.