954 NOTES over KOH pellets, distilled, and stored over molecular sieves 4A. 1,2—Dichloroethane was dried over CaClz, distilled and stored over molecular sieves 4A. Sulfur trioxide was obtained by distillation of 60% fuming sulfuric acid. IR spectra were recorded on a JASCO IR-S spectrophotometer. Thin-layer chromatography was per- formed on 0.25 mm-thick cellulose plates (Cellulose Mikrokristallin, E. Merck). Compounds were visualized by UV fluorescence or ...
