Asymmetric oxidation of 3-alkyl-1,2-cyclopentanediones. Part 2: Oxidative ring cleavage of 3-alkyl-1,2-cyclopentanediones: synthesis of 2-alkyl-γ-lactone acids
Ti(OiPr)4/diethyl tartrate/tBuOOH system oxidizes 3-alkyl-1,2-cyclopentanediones resulting in hydroxylated ringcleavage products 2-alkyl-γ-lactone acids, in high enantioselectivity (∼95% ee) and satisfactory isolated yields (up to 55%).
Ti(O i Pr)4 /酒石酸二乙酯/ t BuOOH体系氧化3-烷基-1,2-环戊二酮,生成羟化的环裂解产物2-烷基-γ-内酯酸,对映体选择性高(〜95%ee),令人满意单产(最高55%)。
Aqueous organocatalyzed aldol reaction of glyoxylic acid for the enantioselective synthesis of α-hydroxy-γ-keto acids
作者:Fernando J. N. Moles、Gabriela Guillena、Carmen Nájera
DOI:10.1039/c3ra46800c
日期:——
N-Tosyl-(Sa)-binam-L-prolinamide is an efficientcatalyst for the aqueousaldolreaction, between glyoxylic acid, as monohydrate or aqueous solution, and ketones. This reaction led to the formation of chiral α-hydroxy-γ-keto carboxylic acids in high levels of diastereo- and enantioselectivities achieving mainly anti aldol products.