Effective synthesis of cis-3-hexen-1-yl acetate via transesterification over KOH/γ-Al2O3: Structure and catalytic performance

Cis-3-hexen-1-yl acetate is a significant green note flavor compound and widely used in the food and cosmetic industry. In this research, a series of solid base KOH/gamma-Al2O3 have been prepared and been utilized for the synthesis of cis-3-hexen-1-yl acetate via transesterification from cis-3-hexen-1-yl and ethyl acetate. The catalysts were also characterized by several physic-chemical techniques such as X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, N-2 adsorption, CO2-temperature-programmed desorption (CO2-TPD), and X-ray fluorescence (XRF). 30%KOH/Al2O3 was suggested to be the best conversion due to the cis-3-hexen-1-ol conversion of 59.3% at a temperature 88 degrees C within 2 h. Characterization results showed that KOH transformed into Al-O-K and K2O.CO2 species during the calcination process. It was confirmed that K2O.CO2 disappeared and Al-O-K groups existed on the surface of the water-washing 30%KOH/Al2O3 which was inactive for transesterification. K2O.CO2 species might be the major active species on KOH/Al2O3, and Al-O-K groups was inactive for cis-3-hexen-yl acetate synthesis. (c) 2013 Elsevier B.V. All rights reserved.