A convenient one-pot procedure to afford bicyclic molecules by stereospecific iron carbonyl mediated [6 + 2] ene-type cyclization: a possible approach to gelsemine.

A convenient one-pot procedure to prepare angularly substituted bicyclic and tricyclic molecules with excellent diastereoselectivity in good yield was developed, by Fe(CO)5 promoted cyclization. Three transformations (complexation, isomerization, and cyclization) were realized in a single operation. The product of this reaction may be a precursor for synthesis of the alkaloid gelsemine.