pyrroles. -Best results in regard to the yield are obtained when the cyclization reaction is carried out at 0 °C. Higher temperatures give more complexe mixtures. The cyclization is not successful using other Lewis acids such as SnCl4 or ZnCl2. -(KOBAYASHI*, K.; TAKANOHASHI, A.; HIMEI, Y.; SANO, T.; FUKAMACHI, S.; MORIKAWA, O.; KONISHI, H.; Heterocycles 71 (2007) 12, 2717-2720; Dep. Mater. Sci., Fac. Eng., Tottori Univ., Koyama, Tottori 680, Japan; Eng.) -H. Haber 13-153