Ba. Chauder et al., Directed ortho metalation reactions of aryl O-carbamates; a regiospecific synthesis of 2,2-disubstituted 2H-1-benzopyrans, SYNTHESIS-S, (1), 2001, pp. 140-144
one-pot regiocontrolled synthesis of 2,2-disubstituted 2H-1-benzopyrans 5 f
rom aryl O-carbamates 4 using the directed ortho metalation reaction is des
cribed and constitutes an advantageous complement to classical routes for t
his class of heterocycles.