title: Synthesis of tetracyclic chromenones via platinum(II) chloride catalysed cascade cyclization of enediyne-enones.
abstract: PtCl2 catalysed cascade cyclization of an enediyne-enone system to afford a tetracyclic chromenone is reported, which proceeds through two consecutive highly regioselective 6-endo-dig cyclizations in a single step with the formation of two new C-C bonds and two new rings in excellent yield. A mechanism for this transformation is proposed based on the isolated intermediates.
authors.affiliation: Organic Chemistry Division, CSIR - Central Leather Research Institute, Adyar, Chennai, 600020, Tamilnadu, India. ptperumal@gmail.com.
authors.forename: Mahalingam
authors.initials: M
authors.lastname: Sivaraman
authors.forename: Paramasivan T
authors.initials: PT
authors.lastname: Perumal