Polycyclic chromans via novel tricyclic-2-phenyl-4H-1,3,2-benzodioxaborins

Article abstract of DOI:10.1016/S0040-4039(00)73073-5

This paper describes a straightforward synthesis of complex polycyclic chromans. They are prepared from novel tricyclic-2-phenyl-4H-1,3,2-benzodioxaborins via a bicyclic orthoquinone-methide intermediate generated in situ under thermolysis or Lewis acid condition. The dioxaborins react with various allyl trimethylsilanes or with ethyl vinyl ether to give polycyclic chromans after acid cyclization or directly.