“…. 30 The title compound (26.73 g, 91% yield as a brown solid) was obtained from 5 (20 g, 119 mmol) using N-bromosuccinimide (23.15 g, 131.0 mmol) by the same method that was used for the preparation of 16a: mp 158−161 °C; 1 H NMR (500 MHz, DMSOd 6 ) δ 13.78 (s, 1H), 4.01 (s, 3H), 2.63−2.36 (m, 2H), 1.59 (h, J = 7.4 Hz, 2H), 0.90 (t, J = 7.4 Hz, 3H); 13…”