76397-53-0Relevant academic research and scientific papers
Dess-Martin periodinane oxidative rearrangement for preparation of α-keto thioesters
Sanichar, Randy,Carroll, Ciaran,Kimmis, Ryan,Reiz, Bela,Vederas, John C.
supporting information, p. 593 - 597 (2018/02/09)
A Dess-Martin Periodinane (DMP) mediated oxidative rearrangement reaction was uncovered. The reaction proceeds via oxidation of a β-hydroxy thioester to a β-keto thioester, followed by an α-hydroxylation and then further oxidation to form a vicinal thioester tricarbonyl. This product then rearranges, extruding CO2, to form an α-keto product. The mechanism of the rearrangement was elucidated using 13C labelling and analysis of the intermediates as well as the products of the reaction. This efficient process allows for easy preparation of α-keto thioesters which are potential intermediates in the synthesis of pharmaceutically important heterocyclic scaffolds such as quinoxalinones.
Understanding Programming of Fungal Iterative Polyketide Synthases: The Biochemical Basis for Regioselectivity by the Methyltransferase Domain in the Lovastatin Megasynthase
Cacho, Ralph A.,Thuss, Justin,Xu, Wei,Sanichar, Randy,Gao, Zhizeng,Nguyen, Allison,Vederas, John C.,Tang, Yi
supporting information, p. 15688 - 15691 (2016/01/09)
Highly reducing polyketide synthases (HR-PKSs) from fungi synthesize complex natural products using a single set of domains in a highly programmed, iterative fashion. The most enigmatic feature of HR-PKSs is how tailoring domains function selectively during different iterations of chain elongation to afford structural diversity. Using the lovastatin nonaketide synthase LovB as a model system and a variety of acyl substrates, we characterized the substrate specificity of the LovB methyltransferase (MT) domain. We showed that, while the MT domain displays methylation activity toward different β-ketoacyl groups, it is exceptionally selective toward its naturally programmed β-keto-dienyltetraketide substrate with respect to both chain length and functionalization. Accompanying characterization of the ketoreductase (KR) domain displays broader substrate specificity toward different β-ketoacyl groups. Our studies indicate that selective modifications by tailoring domains, such as the MTs, are achieved by higher kinetic efficiency on a particular substrate relative to the rate of transformation by other competing domains.
A Mild and Efficient Method for Selective Acetylation of Amines
Yang, Shyh-Chyun,Wang, Huey-Min,Chen, Ling-Ching
, p. 585 - 588 (2007/10/02)
Primary and secondary amines were acetylated under mild conditions by means of 3-acetyl-1,3-thiazolidine-2-thione .The reaction was successfully applied to selective acetylation of a primary amino group of diamines containing a primary and a secondary amino groups or exclusive N-acetylation of amino alcohols.Key Words Selective acetylation; 3-Acetyl-1,3-thiazolidine-2-thione.
SYNTHETIC CONTROL LEADING TO CHIRAL COMPOUNDS
Mukaiyama, Teruaki,Iwasawa, Nobuharu,Stevens, Rodney W.,Haga, Toru
, p. 1381 - 1390 (2007/10/02)
A highly diastereoselective cross aldol reaction is developed using divalent tin enolates formed from stannous trifluoromethanesulfonate and carbonyl compounds.The reaction is extended to a highly enantioselective cross aldol reaction employing chiral dia
3-AMINOACYL-TETRAHYDROTHIAZOLE-2-THIONE AS AN ACTIVE AMIDE FOR PEPTIDE SYNTHESIS (I)
Chung-hsi, Li,Yuen-hwa, Yieh,Yao, Lin,Yong-jun, Lu,Ai-hsueh, Chi,Chi-yi, Hsing
, p. 3467 - 3470 (2007/10/02)
3-Aminoacyl-tetrahydrothiazole-2-thione can be used as an active amide for peptide synthesis.A series of peptides have been synthesized with satisfactory yields by this methods.
Formation and Rearrangement of Cyclic Semi-aminals with α-Mercapto Groups
Kucklaender, Uwe,Edoho, Edoho J.,Rinus, Olaf,Massa, Werner
, p. 3405 - 3415 (2007/10/02)
Reaction of thioacetic acid, thiobenzoic acid as well as 2-aminothiophenol with racemic cyclic semi-aminal 3 takes a diastereoselective course to racemic 4a, b, c.The ambident thiazolidine-2-thione reacts analogously, however by attack of nitrogen yielding 4d.The possibilities for rearrangement of adducts 4 are discussed and the structure of the rearranged products is examinated by x-ray analysis of 9c as well as by 13C NMR spectroscopy.The course of the diastereoselective rearrangement to the racemic mixture (α/β) of 2-azaspirononenes 9a-d is discussed by aid of the results.
