2-Trimethylsilyloxy-l,3-butadiene, reaction

The photoreactions are carried out in 50-100 mL of 1,2-dimethoxyethane or cyclohexane solutions, flushed with Ar (15 min) prior to irradiation, with 0.1 M enone and 0.5 M 2-trimethylsilyloxy-l.3-butadiene reaction temp 8-10°C (water-cooled reaction vessel) reaction time 40-48 h. The reactions are run in a Rayonet reactor equipped with RPR 3000- (quartz vessel used) or —3500 A lamps (Pyrex vessel used) and monitored by GC and TLC. Purification and separation of the product mixtures are performed by flash chromatography (silica gel, 50-fold). 

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