title: Base-Mediated Cyclocondensation of Salicylaldehydes and 2-Bromoallyl Sulfones for the Synthesis of 3-Sulfonylchromene Derivatives and Their Regioselective Friedel-Crafts Heteroarylation Reactions.
abstract: Cesium carbonate-mediated reaction of 2-hydroxybenzaldehydes and 2-bromoallyl sulfones afforded 2H- and 4H-chromenol derivatives endowed with a 3-arylsulfonyl group. 2-Bromoallyl sulfones functioned as synthetic equivalents of allenyl sulfones under these conditions. The 2H- and 4H-chromenol derivatives underwent regioselective Friedel-Crafts reactions with heteroarenes in the presence of p-toluenesulfonic acid to afford 4-heteroaryl-4H-chromene derivatives in excellent yields.
authors.affiliation: Medicinal Chemistry and Pharmacology Division, CSIR-Indian Institute of Chemical Technology , Hyderabad 500 007, India.
authors.forename: Anand
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Medicinal Chemistry and Pharmacology Division, CSIR-Indian Institute of Chemical Technology , Hyderabad 500 007, India.
authors.forename: Srinivas
authors.initials: S
authors.lastname: Thadkapally
authors.affiliation: Medicinal Chemistry and Pharmacology Division, CSIR-Indian Institute of Chemical Technology , Hyderabad 500 007, India.
authors.forename: Rajeev S
authors.initials: RS
authors.lastname: Menon