许多天然产物(如黄酮、香豆素、苯丙素)分子结构中含有2-[-1′-(4′-甲基-3′-戊烯基)]-2-甲基苯并呋喃(1a)和1b的结构单元,如,具有抗肿瘤生物活性的Sanggenol L 4和Kuwanol 5[1].因此寻找1a和1b便利有效的合成方法具有重要的合成价值.我们采用2,4,6-三羟基苯乙酮(2a)[或2,4-二羟基苯乙酮(2b)]为原料,与柠檬醛3在有机碱(吡啶、三乙胺、N,N-二乙基苯胺)的作用下,一步反应以较好的收率40%～70%分别获得1a和1b结构单元.……
＜正＞ The geranylated chalcone 1,3′-geranyl-2′,3,4,4′-tetvahydroxychalcone with high 5α-reductase inhibitory pro...
LIU, Hong-Xing HUANG, Chu-Sheng CHEN, Xi-Hui ZHU, Yan-Yun
(Applied Chemical Institute of Guangxi Teachers'' College, Nanning 530001) (College of Chemistry and Chemical Engineering, Guangxi University, Nanging 530004)
A concise route for the total syntheses of benzopranylchalcones from 2,4,6-trihydroxyacetophone(3) and citral(8), by means of cyclization, methoxy-protection and aldol-condensation is described. Two benzopranylchalcones, Boesenbergin B(1) and Boesenbergin A(2) were synthesized from 2,4,6-(trihydroxyacetophone)(3), citral(8) and benzaldehyde(9) via the route. The total yields of compounds 1 and 2 were 26% and 11%, respectively. In the cyclization step, the yields of key intermediates 4 and 7 were 40% and 42%, respectively.
