180475-27-8Relevant academic research and scientific papers
Structural and stereochemical analysis of a modular polyketide synthase ketoreductase domain required for the generation of a cis-alkene
Bonnett, Shilah A.,Whicher, Jonathan R.,Papireddy, Kancharla,Florova, Galina,Smith, Janet L.,Reynolds, Kevin A.
, p. 772 - 783 (2013)
The formation of an activated cis-3-cyclohexylpropenoic acid by Plm1, the first extension module of the phoslactomycin polyketide synthase, is proposed to occur through an L-3-hydroxyacyl-intermediate as a result of ketoreduction by an A-type ketoreductase (KR). Here, we demonstrate that the KR domain of Plm1 (PlmKR1) catalyzes the formation of an L-3-hydroxyacyl product. The crystal structure of PlmKR1 revealed a well-ordered active site with a nearby Trp residue characteristic of A-type KRs. Structural comparison of PlmKR1 with B-type KRs that produce D-3-hydroxyacyl intermediates revealed significant differences. The active site of cofactor-bound A-type KRs is in a catalysis-ready state, whereas cofactor-bound B-type KRs are in a precatalytic state. Furthermore, the closed lid loop in substrate-bound A-type KRs restricts active site access from all but one direction, which is proposed to control the stereochemistry of ketoreduction.
Enantioselective synthesis of α-amino acids from N-tosyloxy β-lactams derived from β-keto esters
Durham, Timothy B.,Miller, Marvin J.
, p. 27 - 34 (2007/10/03)
A novel synthetic sequence has been developed to convert simple β-keto esters into enantiomerically enriched α-amino acids. The key features of this sequence include the addition of azide to the C3 position of β-keto ester derived N-tosyloxy-β-lactams through a concomitant nucleophilic addition/N-O bond reduction reaction, a mild CsF-induced N1 benzylation of α-azido monocyclic β-lactams, the preparation of α-keto-β-lactams through a novel four-step sequence from the corresponding 3-azido-1-benzyl-β-lactams, and TEMPO-mediated ring expansion of these compounds to the corresponding N-carboxy anhydrides (NCAs). In addition, the synthesis, isolation, and characterization of unusual 3-imino and 3-chloramino-β-lactams is reported.
Indium mediated reactions in water: Synthesis of β-hydroxyl esters
Yi, Xiang-Hui,Meng, Yue,Li, Chao-Jun
, p. 4731 - 4734 (2007/10/03)
A variety of β-hydroxyl esters were synthesized efficiently through indium mediated carbon-carbon bond formation in water followed by ozonolysis.
