Synthesis of carbo- and heterocyclic aldehydes bearing an adjacent donor group - Ozonolysis versus OsO4/KIO4-oxidation

Article abstract of DOI:10.1007/s00706-004-0163-0

The synthesis of carbo- and heterocyclic aldehydes bearing an ipso-methoxy group is investigated. The synthetic sequence is based on an initial Grignard addition of an olefin to a cyclic ketone followed by methylation of the resulting tertiary alcohol. The terminal olefin serves as precursor for the aldehyde functionality. Oxidation by ozonolysis turned out to depend significantly on the distance of the donor methoxy group. The observed side reactions could be circumvented by applying a one-pot OsO₄ mediated diol formation followed by Malaprade oxidation using KIO₄. A series of carbo- and heterocyclic precursors were successfully converted to the title products. Springer-Verlag 2004.