A new synthetic route for biologically interesting pyranocarbazoles was developed by reaction of 2- or 4-hydroxycarbazole with α,β-unsaturated aldehydes in the presence of ethylenediamine diacetate (EDDA). The key strategy of this methodology is a formal [3+3] cycloaddition via domino aldol-type/6π-electrocyclization. The synthesized pyranocarbazoles can be converted into derivatives bearing substituents on the carbazole and pyran rings.
Key words
pyranocarbazoles - ethylenediamine diacetate - domino reaction - heterocycles - cyclization
