Ruthenium Tetroxide Catalyzed Oxidations of Aromatic and Heteroaromatic Rings

Article abstract of DOI:10.1021/jo00162a009

In order to determine the absolute stereochemistry of several aromatic and heterocyclic alcohols, it was necessary to oxidize protected derivatives to mono- and dicarboxylic acids of established configuration.A recently improved procedure utilizing aqueous sodium periodate in the presence of catalytic quantities of ruthenium tetroxide has been used to oxidize a number of compounds to the desired acids in satisfactory yield.The oxidations of (-)-α-(2-thienyl)ethyl acetate, (-)-α-(2-furyl)ethyl acetate, and several substituted α-phenylethyl acetates to (S)-O-acetyllactic acid have been used to confirm their absolute stereochemistries.However, α-(2-pyridyl)ethyl acetate was inert, and α-(3-phenanthryl)ethyl acetate yielded a complex reaction mixture.Prior conversion of the pyridine derivative to its N-oxide and of the substituted phenanthrene to the 9,10-dibromo derivative permitted each compound to be degraded to O-acetyllactic acid.