193214-07-2Relevant academic research and scientific papers
Amine-catalyzed direct aldol reactions of hydroxy- and dihydroxyacetone: Biomimetic synthesis of carbohydrates
Popik, Oskar,Pasternak-Suder, Monika,Le?niak, Katarzyna,Jawiczuk, Magdalena,Górecki, Marcin,Frelek, Jadwiga,Mlynarski, Jacek
, p. 5728 - 5739 (2014/07/08)
This article presents comprehensive studies on the application of primary, secondary, and tertiary amines as efficient organocatalysts for the de novo synthesis of ketoses and deoxyketoses. Mimicking the actions of aldolase enzymes, the synthesis of selected carbohydrates was accomplished in aqueous media by using proline- and serine-based organocatalysts. The presented methodology also provides direct access to unnatural l-carbohydrates from the (S)-glyceraldehyde precursor. Determination of the absolute configuration of all obtained sugars was feasible using a methodology consisting of concerted ECD and VCD spectroscopy.
Synthesis of chondramide a analogues with modified β-tyrosine and their biological evaluation
Zhdanko, Alexander,Schmauder, Anke,Ma, Christopher I.,Sibley, L. David,Sept, David,Sasse, Florenz,Maier, Martin E.
supporting information; experimental part, p. 13349 - 13357 (2012/02/14)
Starting from cinnamates 9, obtained by Wittig reaction or Heck coupling, the diols 17 were prepared by asymmetric dihydroxylation. This was followed by a regioselective substitution of the 3-OH group with hydrazoic acid under Mitsunobu conditions. Methylation of the 2-OH group and reduction of the azide group led to the β-tyrosine derivatives 8. Condensation with the dipeptide acid 6 furnished the tripeptide part of the chondramides. The derived acids 21 were combined with the hydroxy ester 7 to the esters 22. Cleavage of the tert-butyl groups and intramolecular lactam formation gave rise to the chondramide A analogues 2 b-k. Growth inhibition assays showed most of the analogues to be biologically active. Some of them even reach the activity of jasplakinolide. It can be concluded that the 4-position of the aryl ring in the β-tyrosine of chondramide A tolerates structural modifications quite well.
Highly selective chirally templated isomunchnone cycloadditions of achiral aldehydes: Synthesis of an enantiopure α,β-Dihydroxyacid
Drew, Michael G. B.,Fengler-Veith, Marion,Harwood, Laurence M.,Jahans, Archie W.
, p. 4521 - 4524 (2007/10/03)
Additions of p-nitro- and p-methoxybenzaldehyde to isomunchnone derivatives of (5S)-phenyloxazin-3-one and -2,3-dione led to corresponding adducts (3,4,6) with excellent diastereofacial and exo-selectivity. Hydrolysis and subsequent cleavage of adduct 3 permitted recovery of the original template and furnished dihydroxyacid 9 that was transformed into the known ethyl ester 10. Comparison of its optical rotation with the literature value confirmed its high optical purity.
