Lithium acetylides with functional groups such as orthoester or acetal group in the molecule react with trialkylboranes with the migration of alkyl groups. The oxidation of the intermediates obtained from triethyl orthopropiolate gives a mixture of β-hydroxy-and α,β,-unsaturated esters, and the oxidation of those from propiolaldehyde diethylacetal gives (E)-1-ethoxy-1-alken-3-ones respectively.
Chemoselective in situ protection of aldehydes and ketones using titanium tetrakis(dialkylamides)
作者:Manfred T. Reetz、Brend Wenderoth、Roland Peter
DOI:10.1039/c39830000406
日期:——
Titaniumtetrakis(dialkylamides) are chemoselective protective agents for carbonyl compounds, so that such reactions as Grignard and aldol additions can be induced to occur at ketone groups in the presence of aldehydes in a one-pot procedure.