Stereoselective Direct Amine-Catalyzed Decarboxylative Aldol Addition
摘要:
A stereoselective decarboxylative aldol addition of beta- and alpha-keto acids in the presence of catalytic amounts of amines is described. By the optional deployment of chiral enolizable aldehydes an access to enantiopure configurative defined ketopentoses, ketohexoses, or ketoheptoses is given.
An operationally simple protocol is reported to generate an α-hydroxyacyl anion by the decarboxylation of dihydroxyfumaricacid. To date, the “missing” utilization of the hydroxyacyl anion in highly chemo- and stereoselective cascade reactions enables short and direct construction of carbohydrates.
An efficient gram scale synthesis of 3-fluoro-1-hydroxyacetone phosphate (FHAP) has been developed. As a close analog to dihydroxyacetone phosphate, FHAP was used as a novel donor substrate for rabbit muscle aldolase catalyzed reactions. The different binding affinities of the gem-diol and keto form of FHAP were studied by 19F-NMR.
A two-step reaction sequence starting with the indium-mediatedallenylation of aldehydes with 4-bromo-2-butyn-1-ols and subsequent ozonolysis of the resulting allenylic product was developed to generate a variety of dihydroxyacetone derivatives. The regioselectivity of the indium-promoted C–C bond-forming reaction can be manipulated through hydroxy protecting groups on 4-bromo-2-butyn-1-ol, yielding
Stereoselective Direct Amine-Catalyzed Decarboxylative Aldol Addition
作者:Kerstin Rohr、Rainer Mahrwald
DOI:10.1021/ol200412r
日期:2011.4.1
A stereoselective decarboxylative aldol addition of beta- and alpha-keto acids in the presence of catalytic amounts of amines is described. By the optional deployment of chiral enolizable aldehydes an access to enantiopure configurative defined ketopentoses, ketohexoses, or ketoheptoses is given.