“…Dehydration of 6 with p-tosic acid in refluxing benzene for 1 h gave 7 (98%): mp 167-169 °C (lit. * 23 mp 168-169 °C); NMR (CDCI3) 2.28-2.67 (m, 2, Hn), 3.00 (d, 2, Jw " = 8 Hz, H10), 5.92-6.25 (m, 1, Hr>), 6.62 (d, 1, J1213 = 10 Hz', Hla), 7.41-7.73 (m, 4, ,, ), 8.17 (s, 1, Hu), 8.25 (s, 1,' H9), 8.40-8.80 (m, 4, ^,ß)• Method C. A solution of 4 (500 mg, 1.9 mmol) in benzene (150 mL) was heated with DDQ (410 mg) at reflux for 10 min. NMR analysis of the crude product isolated by conventional workup showed the presence of 4 (83%), 7 (8%), and 1 (8%).…”