Synthetic methods for unsymmetrically-substituted 1, 2, 4, 5-tetroxanes and of 1, 2, 4, 5, 7-pentoxocanes

摘要

Ozonolysis of vinyl ethers 1a-c in the presence of hydrogen peroxide in diethyl ether gave the corresponding 1, 1-bis(hydroperoxide)s 2a-c. Subsequent trimethylsilylation, followed by the TMSOTf-catalyzed cyclocondensation with carbonyl compounds gave the unsymmetrically-substituted 1, 2, 4, 5-tetroxanes 5-14. Similarly, the 1, 2, 4, 5, 7-pentoxocanes 18, 19 were prepared by the reaction of an #alpha#, #alpha#'-bis(trimethylsilylperoxy) ether 17 and carbonyl compounds. The tetroxane 14 showed notable antimalarial activity in vitro and in vivo.