Method of preparing (+)-deoxoartemisinin and selected analogues of (+)-deoxoartemisinin

摘要

This invention is a new method for preparing compounds useful as antimalarial agents having the formula; <IMAGE> wherein R is hydrogen, a linear, branched or cyclo lower alkyl group having 1 to 8 carbon atoms; aminoalkyl; branched aminoalkyl; hydroxyalkyl: alkylcarboxylate or alkylbenzoate groups having 1 to 5 carbon atoms in the alkyl chains; aryl; alkoxy-substituted aryl; heteroaryl; and pyridinium groups. The method comprises treating artemisinic acid with a methylating agent followed by a stereoselective reduction of the methylated compound, subjecting the reduced compound to a Grignard addition followed by chiral photoxidation with subsequent treatment with a cyclization agent.