Glycerol is the main co-product from biodiesel production and has been recognized as a sustainable solvent. Herein, we used glycerol and waste glycerol in synthesis of two bioactive α,β-unsaturated ketones (E,E)-1,5-diphenylpenta-2,4-dien-1-one (1) and (E,E)-2,6-dibenzylidenecyclohexanone (2), using aldol mono- and di-condensation reactions, respectively. Crude yield values were calculated from product mass after precipitation and drying. Purity was measured by High Performance Liquid Chromatography with Photodiode Array (HPLC-PAD) using analytical curves and reference compounds. Glycerol and waste glycerol were able to furnish 1 and 2 in higher crude yields and HPLC-PAD purities values than other protic solvents (ethanol, methanol, PEG-400 and water). In order to investigate reasons of glycerol efficiency when compared to water efficiency, we performed computational calculations using Density Functional Theory (DFT). Theoretical predictions confirmed the E1cB mechanism, as well as favourable energy barrier using glycerol in comparison to water, corroborating their sustainable properties. In addition, waste glycerol from corn and sunflower oil transesterifications were used in the synthesis of 1 and 2 for four recycles, displaying good crude yields and HPLC-purities.

甘油是生物柴油生产的主要副产品，被公认为可持续的溶剂。在本文中，我们使用甘油和废甘油合成了两种具有生物活性的α，β-不饱和酮（E，E）-1,5-diphenylpenta-2,4-dien-1-one（1）和（E，E）- 2,6-二亚苄基环己酮（2），分别使用羟醛单缩合反应和双缩合反应。由沉淀和干燥后的产物质量计算粗品收率值。使用分析曲线和参考化合物，通过带有光电二极管阵列的高效液相色谱仪（HPLC-PAD）测量纯度。甘油和废甘油能够提供1和2与其他质子溶剂（乙醇，甲醇，PEG-400和水）相比，其原油收率和HPLC-PAD纯度更高。为了调查与水效率相比甘油效率的原因，我们使用密度泛函理论（DFT）进行了计算。理论预测证实了E1cB的机理，以及与水相比使用甘油的有利的能量屏障，从而证实了其可持续性。此外，来自玉米和葵花籽油酯交换反应的废甘油用于1和2的合成中，共进行四个循环，显示出良好的原油收率和HPLC纯度。