Dearomative, Intramolecular Bromoetherification of Carbohydrate‐derived Glycosyl Furans: Access to Enantiopure 6‐Bromo‐Furo[3,2‐<i>b</i>]furans

Abstract Glycosyl furans represent versatile chiral platform molecules that can be readily accessed via the Garcia Gonzalez reaction. Herein, we report a dearomative, intramolecular bromoetherification of carbohydrate‐derived glycosyl furans to generate enantiopure 6‐bromo‐furo[3,2‐ b ]furans in up to 69% yield. The method employs N ‐Br aromatic amides as competent electrophilic halogenating agents that outpace other known reagents. The method works for glycosyl furans derived from the Garcia Gonzalez reactions of various active methylene compounds and unprotected sugars. Further functionalization of the C−Br bond of the 6‐bromo‐furo[3,2‐ b ]furans is explored as well.