title: A facile access to substituted benzo[a]fluorenes from o-alkynylbenzaldehydes via in situ formed acetals.
abstract: In situ formed acetal changes the course of Brønsted acid-catalyzed reaction of ortho-alkynylbenzaldehydes with arylalkynes altogether. By utilizing this, an efficient domino approach for the regioselective synthesis of substituted benzo[a]fluorenes has been developed under mild reaction conditions. In situ formed acetal facilitates the intermolecular heteroalkyne metathesis and subsequent trans to cis isomerization of a double bond to effect the intramolecular annulation.
authors.affiliation: School of Chemistry, University of Hyderabad, Gachibowli, Hyderabad, India. rbsc@uohyd.ernet.in.
authors.forename: Seetharaman
authors.initials: S
authors.lastname: Manojveer
authors.forename: Rengarajan
authors.initials: R
authors.lastname: Balamurugan