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.
A containing halogen light active 2 - oxo - 1, 3 - oxazine compounds and its preparation method and application
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Paragraph 0095-0098, (2017/08/23)
The invention discloses a 2-carbonyl-1,3-oxazine compound and a preparation method therefor and application thereof. The structural formula of the 2-carbonyl-1,3-oxazine compound is shown in a formula II. The preparation method comprises: carrying out a reaction on a compound shown in a formula I and N-bromoacetamide (or 1,3-dibromo-5,5-dimethyl hydantoin) under the action of a scandium trifluoromethanesulfonate/monophosphine ligand. The photoactive 2-carbonyl-1,3-oxazine compound provided by the invention can be used for conveniently obtaining compounds containing 1,3-hydroxylamine structures and functionalized heterocyclic compounds through further conversion reactions, and meanwhile, a bromine atom can be introduced into the reaction. The functional groups can be further converted. Other functional groups are introduced, so that the compound has huge application value. According to the method provided by the invention, raw materials are easily synthesized, the reaction condition is mild, the operation is simple and convenient, the region selectivity is high, the enantioselectivty can reach up to over 99%, and the output reaches up to 72%. The formulae are shown in the description.