Stereospecific [3+2] cycloaddition of 1,2-cyclopropanated sugars and ketones catalyzed by SnCl4: an efficient synthesis of multi-substituted perhydrofuro[2,3-b]furans and perhydrofuro[2,3-b]pyrans.

Stereospecific [3+2] cycloaddition of 1,2-cyclopropanated sugars and ketones catalyzed by SnCl4 is described. The method offers multi-substituted perhydrofuro[2,3-b]furans (bis-THFs) and perhydrofuro[2,3-b]pyrans containing a quaternary carbon chiral center in good to excellent yields.