DMEG; triethylamine in dichloromethane T=20°C; Dehydration; Cyclization; 22 h;

1: 1) SOCl2 / 1) CH2Cl2, reflux, 1 h, 2) CH2Cl2, reflux, 5 h 2: 1) p-TsOH, 2) LiAlH4 / 1) ethylene glycol/toluene, overnight, 2) ether, reflux, 8 h View Scheme