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.
![Graphical abstract: 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](http://hg.y866.cn/compound/lib/scimg/usr/1/C3CC48963A.jpg)
