10340-23-5Relevant articles and documents
An Approach to the Syntheiss of (-)-Lipstatin by Wittig Reaction and Lewis Acid-promoted Cycloaddition
Pons, Jean-Marc,Pommier, Agnes,Lerpiniere, Joan,Kocienski, Philip
, p. 1549 - 1552 (1993)
The β-lactone moiety of (-)-lipstatin 1, a potent inhibitor of pancreatic lipase, is prepared via a Lewis acid-promoted cycloaddition between hexyltrimethylsilyl ketene 3 and the (Z,Z)-dienic aldehyde 4, obtained from hexenal by two stereoselective Wittig reactions.
Exploitation of a Multienzymatic Stereoselective Cascade Process in the Synthesis of 2-Methyl-3-Substituted Tetrahydrofuran Precursors
Brenna, Elisabetta,Crotti, Michele,Gatti, Francesco G.,Marinoni, Ludovico,Monti, Daniela,Quaiato, Sara
, p. 2114 - 2122 (2017)
Enantiopure 2-methyl-3-substituted tetrahydrofurans are key precursors of several biologically active products (drugs, flavors, and agrochemicals). Thus, a stereocontrolled and efficient methodology for the obtainment of these synthons is highly desirable. We exploited a two-step multienzymatic stereoselective cascade reduction of α-bromo-α,β-unsaturated ketones to give the corresponding bromohydrins in good yields, with high ee and de values. The cascade process is catalyzed by an ene-reductase and an alcohol dehydrogenase. Further manipulations of these bromohydrins, by two diastereodivergent routes, allowed the preparation of the tetrahydrofuran synthons. One route is based on a lipase catalyzed cleavage of the protecting group. The second route is characterized by a camphor sulfonic acid mediated isomerization of a β-hydroxyepoxide to give the tetrahydrofuran-2-ol. Finally, the synthesis of the most odorous and pleasant stereoisomer of the roasted meat aroma, i.e., (2S,3R)-2-methyl-3-thioacetate tetrahydrofuran, is reported as well.
NbCl5-Mg reagent system in regio-and stereoselective synthesis of (2Z)-alkenylamines and (3Z)-alkenylols from substituted 2-alkynylamines and 3-alkynylols
Dzhemilev, Usein M.,Gabdullin, Azat M.,Kadikova, Rita N.,Mozgovoj, Oleg S.,Ramazanov, Ilfir R.
supporting information, (2021/07/02)
The reduction of N,N-disubstituted 2-alkynylamines and substituted 3-alkynylols using the NbCl5 –Mg reagent system affords the corresponding dideuterated (2Z)-alkenylamine and (3Z)-alkenylol derivatives in high yields in a regio-and stereoselective manner through the deuterolysis (or hydrolysis). The reaction of substituted propargylamines and homopropargylic alcohols with the in situ generated low-valent niobium complex (based on the reaction of NbCl5 with magnesium metal) is an efficient tool for the synthesis of allylamines and homoallylic alcohols bearing a 1,2-disubstituted double bond. It was found that the well-known approach for the reduction of alkynes based on the use of the TaCl5-Mg reagent system does not work for 2-alkynylamines and 3-alkynylols. Thus, this article reveals a difference in the behavior of two reagent systems—NbCl5-Mg and TaCl5-Mg, in relation to oxygen-and nitrogen-containing alkynes. A regio-and stereoselective method was developed for the synthesis of nitrogen-containing E-β-chlorovinyl sulfides based on the reaction of 2-alkynylamines with three equivalents of methanesulfonyl chloride in the presence of stoichiometric amounts of niobium(V) chloride and magnesium metal in toluene.
Chiral Selenide-Catalyzed Enantioselective Construction of Saturated Trifluoromethylthiolated Azaheterocycles
Luo, Jie,Liu, Yannan,Zhao, Xiaodan
supporting information, p. 3434 - 3437 (2017/07/15)
An indane-based, bifunctional, chiral selenide catalyst has been developed. The new catalyst is efficient for the enantioselective synthesis of saturated azaheterocycles possessing a trifluoromethylthio group. The desired products were obtained in good yields with high diastereo- and enantioselectivities.