340269-76-3Relevant academic research and scientific papers
Enantioselective synthesis of α-stereogenic γ-keto esters via formal umpolung
Prakash, G. K. Surya,Wang, Fang,Zhang, Zhe,Ni, Chuanfa,Haiges, Ralf,Olah, George A.
supporting information; experimental part, p. 3260 - 3263 (2012/09/08)
A feasible method has been developed for the enantioselective synthesis of α-stereogenic γ-keto esters. By employing nitro(phenylsulfonyl) methane as an acyl anion equivalent, the integrated Michael addition reaction-oxidative methanolysis protocol allows the preparation of various γ-keto esters with high optical purities.
Diastereoselective synthesis of substituted tetrahydroquinoline-4-carboxylic esters by a tandem reduction-reductive amination reaction
Bunce,Herron,Johnson,Kotturi
, p. 2822 - 2827 (2007/10/03)
A diastereoselective synthesis of 1-methyl-2-alkyl- and 2-alkyl-1,2,3,4-tetrahydroquinoline-4-carboxylic esters has been developed from methyl (2-nitrophenyl)acetate (1). The method involves alkylation of 1 with an allylic halide, ozonolysis of the double bond, and catalytic hydrogenation. The final hydrogenation initiates a tandem sequence involving (1) reduction of the aromatic nitro group, (2) condensation of the aniline or hydroxylamine8 nitrogen with the side chain carbonyl, (3) reduction of the resulting nitrogen intermediate, and (4) reductive amination of the tetrahydroquinoline with formaldehyde produced in the ozonolysis to give a methyl (±)-1-methyl-2-alkyl-1,2,3,4-tetrahydroquinoline-4-carboxylate. Removal of the formaldehyde prior to hydrogenation gives the simple (±)-2-alkyl derivatives. The products are isolated in high yield as single diastereomers having the C-2 alkyl group cis to the C-4 carboxylic ester. The reaction has been extended to the synthesis of tricyclic structures with similar high diastereoselection.
