in sulfur dioxide absence of moisture; warming from -196°C to room temp. over 15 min, then standing at -10°C for 5 d; product mixt. not sepd., detd. by NMR spectroscopy;

in sulfur dioxide absence of moisture; warming from -196°C to room temp. over 15 min, then standing at -10°C for 5 d; product mixt. not sepd., detd. by NMR spectroscopy;