具有杀虫活性蔗糖酯的合成

分别以酯交换法和酰氯法合成了辛酸蔗糖酯和己酸蔗糖酯两种杀虫活性蔗糖酯,其中酯交换法产物单酯含量高,而酰氯法反应速度快。实验在n(蔗糖):n(辛酸乙酯)=2:1,DMF为溶剂,碳酸钾为催化剂,(98±2)℃条件下反应16 h制备了辛酸蔗糖酯,辛酸乙酯的转化率为68．5％(多酯按二酯计算,下同);在n(蔗糖):n(己酰氯)=2:1,DMF为溶剂、吡啶为助剂,65℃条件下反应1．5 h制备了己酸蔗糖酯,己酰氯的转化率为53．9％。产物经傅里叶红外光谱分析、薄层层析分离和分光光度分析,确定辛酸蔗糖酯和己酸蔗糖酯中n(单酯):n(多酯) 分别为1．48:1和1．37:1。以P(辛酸蔗糖酯)=4 mg／mL水溶液对舞毒蛾(Lymantria dispar)1龄幼虫进行杀虫实验,触杀方式36 h后校正死亡率达72．5％。

Synthesis of Insecticidal Sucrose Esters

Insecticidal sucrose octanoate and sucrose caproate were synthesized by transesterification method or reaction of acid chloride with sucrose. With the former method,yield of monoester was high, and with the latter method the reaction speed was high. Thus, sucrose octanoate was prepared by reacting sucrose and ethyl octanoate in molar ratio 2-1 at about 98℃ for 16 h with DMF as solvent and K2CO3 as catalyst. Conversion of ethyl octanoate was 68. 5% (the polyesters calculated as diester). In the acid chloride method,the molar ratio of sucrose to acid chloride was 2-1,reaction temperature was 65℃ ,and reaction time was 1. 5 h. Conversion of hexanoyl chloride was 53. 9%. Both products were identified and their properties analyzed by IR, TLC and spectrophotometry. The molar ratios of monoester to polyester in sucrose octanoate and sucrose caproate were 1. 48:1 and 1. 37: 1 respectively. The insecticidal activity of the synthetic sucrose octanoate was evaluated at a concentration of 4 mg/ mL. The Lvmantria dispar grubs mortality from its contact toxicity was 72. 5% after 36 h.