No abstract

No abstract

No abstract

A mild, efficient conversion of aromatic aldehydes into their corresponding methyl (or ethyl) esters was achieved by treatment with manganese dioxide and sodium cyanide in methanol (or ethanol) but without the use of acetic acid.Direct functional group conversions under mild conditions are of great significance in organic synthesis. In 1968 Corey and his coworkers reported a onepot, three-step transformation of a,&unsaturated aldehydes into the corresponding methyl esters in good yields, in which acetic acid was used with manganese dioxide and sodium cyanide in methanol.'.' In connection with studies on the synthesis of indole analogues of mycophenolic acid as potential antineoplastic agents, we had occasion to realize the conversion of the indole-3-carboxaldehyde l a into the methyl ester lb. Considering that acetic acid may react with the ethylenic double bond on the side chain in la, we turned to a modified procedure not using acetic acid and, fortunately, found its feasibility for the efficient conversion of aromatic aldehydes, including la, into esters.