Brønsted Acid-Catalyzed Intramolecular Allylic Substitution Reaction of Allylic Alcohols: A Facile Synthesis of 2-Vinylchromans

Brønsted acid-catalyzed intramolecular allylic substitution reaction of secondary and tertiary allylic alcohols has been developed. A variety of 2-vinylchromans were efficiently prepared in moderate to excellent yields. The given method features wide substrate scope, operational simplicity, metal-free, and mild reaction conditions. The practicability of the method was demonstrated by the gram-scale reaction and further derivations of the product. Catalytic asymmetric reaction was preliminarily studied.