“…For 3c: 1 H NMR (500 MHz, C 6 D 6 : CS 2 = 1:1) d 0.62 (s, 6H), 2.69 (m, 1H), 3.59 (s, 3H), 3.64 (s, 3H), 6.72 (d, 1H), 7.07 (s, 1H), 7.16 (d, 1H); 13 C NMR (125 MHz, C 6 D 6 : CS 2 = 1:1) d À1.48 (q), 40.65 (d), 55.40 (q), 55.92 (q), 112.30 (d), 116.02 (d), 126.64, 128.30, 132.94, 136.17 (s), 136.66 (s), 137.48, 137.62 (s), 137.94, 138.53, 139.88, 140.05, 141.43, 142.05, 142.94, 143.05, 143.11, 143.13, 143.22, 143.28, 143.46, 143.48, 143.50, 143.61, 143.69, 143.74, 143.78, 143.89, 143.98, 144.26, 144.29, 145.22, 145.25, 148.52, 149.64 (s) …”