Synthesis of Tertiary α-Hydroxy Acids by Silylene Transfer to α-Keto Esters
摘要:
alpha-Keto esters can be converted into alpha-hydroxy acids in a single flask involving metal-catalyzed silylene transfer, 6 pi-electrocyclization, Ireland-Claisen rearrangement, and hydrolysis. This reaction sequence is stereoselective and tolerates alkyl- and aryl-substituted a-keto ester substrates as well as an alpha-imino ester.
Synthesis of Tertiary α-Hydroxy Acids by Silylene Transfer to α-Keto Esters
摘要:
alpha-Keto esters can be converted into alpha-hydroxy acids in a single flask involving metal-catalyzed silylene transfer, 6 pi-electrocyclization, Ireland-Claisen rearrangement, and hydrolysis. This reaction sequence is stereoselective and tolerates alkyl- and aryl-substituted a-keto ester substrates as well as an alpha-imino ester.
undergoes facile thermal cyclisation affording nitrones 1c and 1d in good yield. Oximes E-5a,b with a terminal methyl substituent on the alkene moiety furnish nitrone only under the influence of an external electrophile [PhSeBr/AgBF4]. A terminal Ph substituent on 5c,d prohibits formation of the cyclic dipole irrespective of reaction conditions, and whilst 5d reacts to afford a bicyclic isoxazolofuranone
Synthesis of γ,δ-unsaturated quaternary α-alkylamino acids using umpolung reaction and Claisen rearrangement
作者:Isao Mizota、Katsuki Tanaka、Makoto Shimizu
DOI:10.1016/j.tetlet.2012.01.133
日期:2012.4
A new synthesis of γ,δ-unsaturated quaternary α-amino acid derivatives was developed utilizing N-alkylation and Claisen rearrangement of allyl α-iminocarboxylates.
Synthesis of Tertiary α-Hydroxy Acids by Silylene Transfer to α-Keto Esters
作者:Brett E. Howard、K. A. Woerpel
DOI:10.1021/ol702148x
日期:2007.10.1
alpha-Keto esters can be converted into alpha-hydroxy acids in a single flask involving metal-catalyzed silylene transfer, 6 pi-electrocyclization, Ireland-Claisen rearrangement, and hydrolysis. This reaction sequence is stereoselective and tolerates alkyl- and aryl-substituted a-keto ester substrates as well as an alpha-imino ester.