56633-73-9Relevant academic research and scientific papers
Efficient synthesis of methyl (S)-4-(1-methylpyrrolidin-2-YL)-3-oxobutanoate as the key intermediate for tropane alkaloid biosynthesis with optically acitve form
Katakam, Nanda Kumar,Seifert, Cole W.,D'Auria, John,Li, Guigen
, p. 604 - 613 (2019/08/01)
Methyl (S)-4-(1-methylpyrrolidin-2-yl)-3-oxobutanoate has been synthesized for enzymatic studies on cyclization enzymes during cocaine biosynthesis in Erythroxylum coca plants. During the present new synthesis, L-proline was first protected with Cbz group and reduced to chiral amino alcohol, which were then followed by Swern oxidation, Wittig reaction and decarboxylative condensation. At the last step, N-methylamino acid precursor was treated with 1,1'-carbonyldiimidazole followed by reacting with methyl potassium malonate to give the 3-oxobutanoate in 54% overall yield. This new strategy has proven to avoid obvious racemization of the L-proline chiral center during the synthesis. In addition, six of the eight synthesis steps were performed via GAP chemistry/technology without the use of column chromatography for purification.
Effective methods for the synthesis of N-methyl β-amino acids from all twenty common α-amino acids using 1,3-oxazolidin-5-ones and 1,3-oxazinan-6-ones
Hughes, Andrew B.,Sleebs, Brad E.
, p. 2611 - 2637 (2007/10/03)
N-Methyl β-amino acids are generally required for application in the synthesis of potentially bioactive modified peptides and other oligomers. Previous work highlighted the reductive cleavage of 1,3-oxazolidin-5-ones to synthesise N-methyl α-amino acids. Starting from α-amino acids, two approaches were used to prepare the corresponding N-methyl β-amino acids. First, α-amino acids were converted to N-methyl α-amino acids by the so-called '1,3-oxazolidin-5-one strategy', and these were then homologated by the Arndt-Eistert procedure to afford N-protected N-methyl β-amino acids derived from the 20 common α-amino acids. These compounds were prepared in yields of 23-57% (relative to N-methyl α-amino acid). In a second approach, twelve N-protected α-amino acids could be directly homologated by the Arndt-Eistert procedure, and the resulting β-amino acids were converted to the 1,3-oxazinan-6-ones in 30-45% yield. Finally, reductive cleavage afforded the desired N-methyl β-amino acids in 41-63% yield. One sterically congested β-amino acid, 3-methyl-3-aminobutanoic acid, did give a high yield (95%) of the 1,3-oxazinan-6-one (65), and subsequent reductive cleavage gave the corresponding AIBN-derived N-methyl β-amino acid 61 in 71% yield (Scheme 2). Thus, our protocols allow the ready preparation of all N-methyl β-amino acids derived from the 20 proteinogenic α-amino acids.
Substituted indole compounds having NOS inhibitory activity
-
Page/Page column 78, (2010/11/24)
The present invention features inhibitors of nitric oxide synthase (NOS), particularly those that selectively inhibit neuronal nitric oxide synthase (nNOS) in preference to other NOS isoforms. The NOS inhibitors of the invention, alone or in combination w
Convenient in situ synthesis of nonracemic N-protected β-amino aldehydes from β-amino acids. Applications in Wittig reactions and heterocycle synthesis
Davies, Simon B.,McKervey, M. Anthony
, p. 1229 - 1232 (2007/10/03)
N-Z-γ-amino alcohols derived from nonracemic β-amino acids are smoothly oxidised by manganese dioxide in acetonitrile to afford aldehydes which can be trapped in situ in Wittig reactions with carbonyl-substituted phosphoranes. The application of this methodology to the synthesis of the alkaloids (S)-(+)-N-BOC-coniine, (S)-(-)-coniceine and a pipecoline precursor is described.
The synthesis of a novel benzodiazocine via an intramolecular Staudinger/aza-Wittig cyclization
O'Neil, Ian A.,Murray, Clare L.,Potter, Andrew J.,Kalindjian, S. Barret
, p. 3609 - 3610 (2007/10/03)
The novel pyrrolobenzodiazocine (1) has been prepared by an intramolecular Staudinger/aza Wittig protocol from the precursor azido aldehyde (2) in a remarkable 93% yield. Aldehyde (2) was prepared by coupling protected homoprolinol with 2-azidobenzoic aci
