Title:Organocatalytic Domino Knoevenagel Hetero-Diels-Alder Reaction for the
Synthesis of Chromenopyran Derivatives
Volume: 22
Issue: 1
Author(s): Sangepu Karthik, L. Vishnu Priya, B. Maheshwar Rao, D. R. Adarsh, B. Sridhar, B. V. Subba Reddy*Pannala Padmaja*
Affiliation:
- Centre for Semio Chemicals, CSIR-Indian Institute of Chemical Technology, Hyderabad-500 007, India
- Centre for Semio Chemicals, CSIR-Indian Institute of Chemical Technology, Hyderabad-500 007, India
Keywords:
O-Alkynyl salicylaldehydes, 1, 3-diketones, fused chromenes, hetero-Diels-Alder reaction, organocatalyst, DLProline, propargyl bromide, cyclohexane-1, 3-dione.
Abstract: An organocatalytic, one-pot four-center two-component coupling reaction has been developed
for the synthesis of tetrahydro-1H,7H-chromeno[3,4-c]chromen-1-one derivatives. The reaction
proceeds smoothly in the presence of 5 mol% DL-Proline in methanol under reflux conditions. This
method involves the Knoevenagel condensation of O-alkynyl tethered 2-hydroxybenzaldehydes with
cyclic 1,3-diketones followed by an intramolecular hetero-Diels-Alder reaction. Novel classes of
oxygen containing polycyclic frameworks are prepared in good yields by using this approach.