Abstract

Strategically positioned arom. rings could switch the polyhydrocarbon chain from its normal extended conformation into folded one by the principle of intramol. recognition phenomena, favoring thus the intramol. reaction if these two arom. rings are correctly functionalized. Based on this conception, a new strategy for the synthesis of macrocyclic diarylheptanoids has been developed and convergent total syntheses of acerogenin C (I) (R = H) (II) and aceroside IV (I) (R = beta -D-glucopyranosyl) (III) were accomplished. Cycloetherification of linear diarylheptanoid: 1-(4-fluoro-3-nitrophenyl)-7-(3-hydroxy-4-methoxyphenyl)-heptan-3-one under mild conditions (CsF, DMF, rt) gave the macrocycle: 4-methoxy-17-nitro-2-oxa-tricyclo (13,2,23,7) eicosa-1(18),3,5,7(20),15(19),16-hexaen-12-one in 95% yield. Removal of nitro group followed by O-demethylation gave II. Glucosidation of II followed by sapon. give III in excellent overall yield. [on SciFinder (R)]

Details

Actions