Abstract:

3-Heptanol, an edible flavor, was synthesized through a nucleophilic addition reaction of ethylmagnesium bromide with n-pentanal. Factors influencing 3-heptanol yield, such as molar ratio of raw materials, refluxing time in preparing ethylmagnesium bromide and refluxing time in its addition reaction with n-pentanal were discussed. The optimal reaction conditions were obtained as follows: mole ratio of n-pentanal, monobromoethane and magnesium 1.0:1.2:1.5, refluxing time in preparing ethylmagnesium bromide 45 min, and refluxing time in preparing 3-heptanol 30 min. The yield of 3-heptanol under such conditions was 87.3%. The target product obtained was subjected to structure characterization by means of GC, IR GC-MS and 1H NMR and its characteristic aroma was evaluated. In addition, this flavor was successfully used in commercial banana essence.

Key words: 3-heptanol, n-pentanal, ethylmagnesium bromide, flavor, synthesis