Facile preparation of allenic hydroxyketones via rearrangement of propargylic alcohols.
[formula: see text] Treatment of tertiary propargylic alcohols 13 with 3-diazo-2-butanone 6 and catalytic dirhodium tetraacetate in benzene gave good yields of the diastereomeric allenic hydroxyketones 14, with, in some cases, good diastereocontrol. These products are presumably formed via the [2,3]-sigmatropic rearrangement of an alpha-propargyloxy enol derivative. This reaction has been extended to the preparation of homoallylic hydroxyketones from allylic alcohols by reaction with 6 and the rhodium catalyst.
Jung
M E
ME
Department of Chemistry and Biochemistry, University of California, Los Angeles 90095-1569, USA. jung@chem.ucla.edu
Pontillo
J
J
D000480:Alkynes / Q000138:chemical synthesis*; D002384:Catalysis; D007659:Ketones / Q000138:chemical synthesis*; D008968:Molecular Conformation; D012238:Rhodium; D013237:Stereoisomerism
D000480:Alkynes; D007659:Ketones; D012238:Rhodium