Lewis acid-promoted alpha-hydroxy beta-dicarbonyl to alpha-ketol ester rearrangement.
The decarbomethoxylation reaction of a substituted alpha-hydroxy-alpha-carbomethoxy pentacyclic substituted ketone, used as an advanced intermediate in the synthesis of the alkaloid aspidophytine, can be elected by heating with MgI(2) in CH(3)CN. The reaction was shown to proceed by a novel alpha-hydroxy beta-dicarbonyl to alpha-ketol ester rearrangement. It was possible to isolate a carbonate intermediate in 75% yield, thereby providing support for the proposed pathway.
Hong
Xuechuan
X
Department of Chemistry, Emory University, Atlanta, GA 30322, USA.
Mejía-Oneto
José M
JM
Padwa
Albert
A