反应详情

By proceeding as in Example 1, but starting with 6-bromo-3-methyl-1,1-diethoxy-3,5-hexadiene (0.43 g; 1.63 mmol) and an excess of acetone (0.4 g i.e. 4 equivalents), 1,1-diethoxy-3,7-dimethyl-7-hydroxy-3,5-octadiene, or C10 diethyl hydroxyacetal, (0.4 g) is obtained. After hydrolysis and purification by flash chromatography, eluting with a mixture of petroleum ether and diethyl ether (96/4 by volume), this compound yields dehydrocitral (0.121 g). The yield is 49.6%, based on the 6-bromo-3-methyl-1,1-diethoxy-3,5-hexadiene employed. The structure of the product obtained is confirmed by the infrared spectrum and the proton nuclear magnetic resonance spectrum.