S1 Supporting Information for Domino Prins/Pinacol reaction for the stereoselective synthesis of spiro[pyran-4,4'-quinoline]-2',3'-dione derivatives B. V. Subba Reddy, [a]* S. Gopal Reddy, [a,b] M. Durga Prasad, [a] Manika Pal Bhadra [b] B. Sridhar [c] a Natural Product Chemistry, b Centre for Chemical Biology, c Laboratory of X-ray Crystallography, CSIR-Indian Institute of Chemical Technology, Hyderabad –500 007, India. E-mail:basireddy@iict.res.in. OH HO DCM, 0 o C 3 4 BF 3 .OEt 2 5 N O N O O O R R-CHO Table of Contents 1. General procedure..........................................................................S2-S4 2. Characterization data of 5(a-r) & 3...............................................S4-S12 3. Copies of 1 H & 13 C NMR spectra of 5(a-r) & 3..........................S13-S32 Electronic Supplementary Material (ESI) for Organic & Biomolecular Chemistry. This journal is © The Royal Society of Chemistry 2015