Electrophile-Directed Diastereoselective Alkylation of Prochiral Enediolates
作者:Stephen P. Marsden、Rebecca Newton
DOI:10.1021/ja073624e
日期:2007.10.1
Prochiral substituted enediolates undergo diastereoselective alkylation with β-chiral primary iodohydrin derivatives, with selectivities up to 97:3. The most selective reactions occur with dienediolates, but reasonable selectivities can also be obtained with alkyl- and aryl-substituted enediolates. The presence of the lithioalkoxy substituent on the enolate is crucial for selectivity, as is the presence
Efficient Synthesis of Quaternary α-Hydroxy Acids by Alkylation of α-Ketoamide-Derived Dienediolates
作者:Stephen P. Marsden、Rebecca Newton
DOI:10.1055/s-2005-918481
日期:——
Double deprotonation of α-ketoamides generates dienediolates, which undergo regioselective α-alkylation to yield α-substituted-α-hydroxy-β,γ-unsaturated amides. 1,2-Disubstituted alkenes are generated exclusively as the E-isomer. 1,1-Disubstituted and 1,1,2-trisubstituted olefins can also be prepared. The amides can be readily converted to the corresponding acids.