Yingzhaosu A analogues: synthesis by the ozonolysis of unsaturated hydroperoxides, structural analysis and determination of anti-malarial activity
摘要:
Ozone-mediated cyclization of a series of unsaturated hydroperoxides 7, prepared from dienes 2, afforded the corresponding yingzhaosu A analogues 9 in moderate to high yield. X-Ray crystallographic analysis of two yingzhaosu A analogues, endo-9f and 13, showed that the 2,3-dioxabicyclo[3,3,1]nonane system adopts a chair-boat arrangement. Subsequent treatment of endoperoxides 9 with Ag2O/MeI afforded the expected methyldioxy-substituted cyclic peroxides 14, several of which showed notable anti-malarial activity against P. falciparum in vitro. (C) 2001 Elsevier Science Ltd. All rights reserved.
作者:Hye-Sook Kim、Khurshida Begum、Naoki Ogura、Yusuke Wataya、Takahiro Tokuyasu、Araki Masuyama、Masatomo Nojima、Kevin J. McCullough
DOI:10.1021/jm020208q
日期:2002.10.1
hydroperoxides 1 afforded the expected yingzhaosu A analogues 2. In some cases, however, the corresponding cyclic ethers 5 were formed competitively with the cyclic peroxides 2, the ratios of these two products being a marked function of the structure of the starting materials. Some of the cyclic peroxides 2 showed significant antimalarialactivities in vitro and in vivo.
Ozonolysis of a vinyl ether 2, prepared from dihydrocarvone 1 (a 1:4 mixture of cis- and trans-isomer), in methanol gave two isomeric unsaturated hydroperoxy acetals cis- and trans-3. Iodonium ion- or ozone-mediated cyclizations of the hydroperoxide cis-3 gave the corresponding yingzhaosu A analogues 4 and 6 in moderate yields. The peroxide 8, obtained by the Ag2O-mediated methylation of 6, showed
Ozone-mediated cyclization of a series of unsaturated hydroperoxides 7, prepared from dienes 2, afforded the corresponding yingzhaosu A analogues 9 in moderate to high yield. X-Ray crystallographic analysis of two yingzhaosu A analogues, endo-9f and 13, showed that the 2,3-dioxabicyclo[3,3,1]nonane system adopts a chair-boat arrangement. Subsequent treatment of endoperoxides 9 with Ag2O/MeI afforded the expected methyldioxy-substituted cyclic peroxides 14, several of which showed notable anti-malarial activity against P. falciparum in vitro. (C) 2001 Elsevier Science Ltd. All rights reserved.