Preparation of 1-ethoxy-3-methylbuta-1,2-diene
To a flask cooled to -30° to -40°C and containing 20.0 g (0.11 mole) of 1,1-dichloro-2-ethoxy-3,3-dimethylcyclopropane in 30 ml of dry ether is added dropwise 100 ml of a 1.3 M ethereal n-methyllithium solution (0.13 mole) over a 1 hours period. The reaction mixture is then stirred for an additional 0.5 hours while it is warmed to room temperature. Water is added, the ether is separated, washed with water, dried over sodium carbonate, and then fractionally distilled to afford 7.3 g (59 %) of impure 1-ethoxy-3-methylbuta-1,2-diene, b.p. 55°-57°C (65 mm), nD 1.4344. Redistillation gives a pure product, b.p. 51°C (60 mm), nD 1.4400.
L. Skattebol, J. Org. Chem. 31, 1554 (1966).