... Volume: Page ... a Reagents and conditions: (i) for 2a, (E)-PhCH═CHCO 2 H, POCl 3 , 140 °C, 5 h, 44%; for 2b, MeOH, AcOH, (E)-PhCH═CHCHO, rt, 1 ... a Reagents and conditions: (i) EtOH, N 3 CH 2 CO 2 Et, EtONa, 0 °C, 2h, 55–58%; (ii) p-xylene, 150 °C, 2 h, 78 ...