Tandem Prins cyclization for the Stereo selective synthesis of 3,6-dihydro-2H-pyran scaffolds

G Reddy, B Sreedhar, K Rao, K Murali, Y Reddy, T Sreelatha, T Veera Reddy, B Reddy
A wide array of aldehydes undergo smooth cross-coupling with 3-methylene-5-phenylpent-4-yn-1-ol in the presence of 10 mol% BF 3 ·OEt 2 at 0 °C in dichloromethane afforded the corresponding 6-phenyl-4-(phenylethynyl)-3,6-dihydro-2H-pyran derivatives in good yields with excellent stereoselectively. This is the first report for the synthesis of 6-phenyl-4-(phenylethynyl)-3,6-dihydro-2H-pyran scaffolds via Prins cyclization protocol.