A concise approach for the frst total synthesis of two naturally occurring flavanoids,（）-malaysianone A（1）and（）-tanariflavanones B（2）,has been accomplished with total yields of 12.9%and 10.4%,respectively.The key steps were regioselective deprotection and regioselective synthesis of 5-formaldehyde-8-hydroxy-2-[40-methyl-30-penteneyl]-dihydro-1-benzopyran（8）.
Jin-Hui YangBing-Bing ChenYi-Min XieYao FengXiao-Qin Ma
A facile approach for the first total synthesis of prenylated flavonoids, （±）-abyssinone-VI-4-O-methyl ether 1, （±）-abyssinone- IV-4＇-O-methyl ether 2, （±）-abyssinone-V-4＇-O-methyl ether 3 and （±）-sigmoidin E 4 has been described. The key intermediate 4-hydroxy-3,5-di-（3-methylbut-2-enyl）benzaldehyde 6 was also first synthesized that features regioselective prenylation of 4-hydroxybenzaldehyde and crystallizing with petroleum ether from the reaction mixture by freeze-out effect.
