三种O－异戊烯基苯丙素类天然产物的首次合成

以香草醛为起始原料，经O－异戊烯基化、Witting反应、水解、还原、氧化等 反应步骤，首次合成了三种苯丙素天然产物boropinalA（1），boropinalC（2） boropinicAcid（3）,有化合物结构均由核磁共振氢谱，质谱及红外光谱确证，用 X射线衍射法测定了3的晶体及分子结构。

First synthesis of three naturally occurring O-prenylated phenylpropanoids

The first synthesis of three naturally occurring phenylpropanoids, boropinol A (1), boropinal C (2) and boropinic acid (3), is described. The reaction of vaniline (4) with prenyl bromide in DMF gave the O prenylated product 5 in 84% yield. Condensation of 5 with Ph 3PCHCO 2Et in DME produced ester 6 in 52% yield. Hydrolysis of 6 with aqueous KOH followed by acidification gave boropinic acid (3) in 91% yield. Compound 3 was obtained as a nice crystal instead of a liquid as that reported in literature. The structure of 3 was confirmed by X ray crystal structural analysis in addition to its solution spectrum data. Reduction of 3 by LiAlH 4 in dry diethyl ether gave a mixture of compound 1 and 7. This mixture was not seperated and was oxidized by K 2Cr 2O 7 in DMSO to give compound 2 in 61% yield. Pure boropinol A (1) was obtained in 70% yield by the reduction of 2 with NaBH 4 in CH 3OH.