A practical enantioselective synthesis of the cigarette beetle sex pheromone serricornin
作者:Philip C.-M. Chan、J.Michael Chong、Karim Kousha
DOI:10.1016/s0040-4020(01)86986-6
日期:1994.2
(4RS,6S,7S)-7-hydroxy-4,6-dimenthyl-3-nonanone (serricornin and its C4-epimer) may be prepared from oxazolidinone 5 in 8 steps with an overall yield of 33%.
Asymmetric aldol reaction of amide enolates bearing -2,5-disubstituted pyrrolidines as chiral auxiliaries
作者:Tsutomu Katsuki、Masaru Yamaguchi
DOI:10.1016/s0040-4039(00)98932-9
日期:——
Condensation of aldehydes with Zr enolate of chiral -propionyl--2,5-disubstituted pyrrolidine proceeded with high diastereo- and diastereoface-selection. Stereoselectivity in the reaction of the corresponding -acetyl compounds was also examined.
The Thioesterase of the Erythromycin-Producing Polyketide Synthase: Influence of Acyl Chain Structure on the Mode of Release of Substrate Analogues from the Acyl Enzyme Intermediates
作者:Kira J. Weissman、Cameron J. Smith、Ulf Hanefeld、Ranjana Aggarwal、Matthew Bycroft、James Staunton、Peter F. Leadlay
synthase (PKS) have demonstrated that the ability of this enzyme to act as a universal decoupler is limited, but stereochemical variation is readily tolerated. Synthetic analogues with all four stereochemical configurations of the natural substrate's 2-methyl-3-hydroxy substitution pattern (1-4; X=p-nitrophenoxy) were substrates for the enzyme.
基因工程化的聚酮化合物的生产主要取决于硫酯酶的活性以释放产品。用来自红霉素聚酮化合物合酶(PKS)的硫酯酶进行的体外研究表明,该酶用作通用解偶联剂的能力有限,但很容易耐受立体化学变异。具有天然底物的2-甲基-3-羟基取代模式(1-4; X =对硝基苯氧基)的所有四个立体化学构型的合成类似物是该酶的底物。
Asymmetric Aldol Reactions Using (<i>S</i>,<i>S</i>)-(<i>+</i>)-Pseudoephedrine-Based Amides: Stereoselective Synthesis of α-Methyl-β-hydroxy Acids, Esters, Ketones, and 1,3-Syn and 1,3-Anti Diols
作者:Jose L. Vicario、Dolores Badía、Esther Domínguez、Mónica Rodríguez、Luisa Carrillo
DOI:10.1021/jo000035h
日期:2000.6.1
reactions is reported. The reaction of (S, S)-(+)-pseudoephedrine-derived propionamide enolates with several aldehydes yielded exclusively one of the four possible diastereomers in good yields, although transmetalation of the firstly generated lithium enolate with a zirconium(II) salt, prior to the addition of the aldehyde, is necessary in order to achieve high syn selectivity. The so-formed syn-alpha-methyl-beta-hydroxy
The thioesterase domain from the pimaricin and erythromycin biosynthetic pathways can catalyze hydrolysis of simple thioester substrates
作者:Krishna K. Sharma、Christopher N. Boddy
DOI:10.1016/j.bmcl.2007.03.060
日期:2007.6
biosynthetic pathways catalyze hydrolysis of a number of simple N-acetylcysteamine thioester derivatives. This study demonstrates that thioesterases are not highly substrate selective in formation of the acyl-enzymeintermediate, in contrast to non-ribosomal peptide synthase thioesterase domains that show very high specificity for substrate loading. This observation has important implications for the