The synthesis of indeno[de]isochromene derivatives from arylvinyl epoxides and carbonyl compounds via tandem Nazarov and oxa-Pictet–Spengler cyclizations†
Abstract
The reaction of aryl vinyl epoxides and carbonyl compounds in the presence of a catalytic amount of BF3·OEt2 to indeno[de]isochromenes via tandem Nazarov and oxa-Pictet–Spengler cyclizations is described. The protocol used was operationally simple and the synthesis generated three bonds (two C–C and one C–O), thereby providing a structural skeleton of pharmaceutical interest and natural-product-like polycyclic frameworks.