Preparation of 1,1-diethoxyethene 610.4 g (4.0 mol) of chloroacetaldehyde diethyl acetal, 800 g (12.0 mol) of powdered technical grade potassium hydroxide, 32 g of polyethylene glycol 1000 dimethyl ether and 88 g (1.0 mol) of 2-methyl-2-butanol were heated to reflux in 1.2 l of tert.-butyl methyl ether while stirring. After six hours the reaction was stopped, the salts filtered off and the reaction mixture distilled at reduced pressure (5 kPa). 326 g (72.5% of theoretical) of 1,1-diethoxyethene (b.p. 49?? C./5 kPa) were obtained.
