نتایج جستجو برای: 3 methylbut 1 ene
تعداد نتایج: 3594320 فیلتر نتایج به سال:
Sixteen compounds were isolated from the leaves and stems of Murrayatetramera Huang. Based on the NMR and MS spectral results, the structures were determined. It was confirmed that the isolated compounds included three new compounds (9, 10 and 13) and one new natural product (8), which were identified asmurratetra A (9), murratetra B (10), murratetra C (13) and [2-(7-methoxy-2-oxochromen-8-yl)-...
moderate to excellent entantio- and stereoselectivities (ee’s 54-100%) were observed in ple catalyzed hydrolysis of (±)-ethyl 5-oxo-endo-tricyclo[5.2.1.02,6] deca-8-ene-2-carboxylate 5 and the structurally related open chain bicyclic structures (±)-ethyl 3-acetylbicyclo[2.2.1]hept-5-ene-2-carboxylates 7, 9 and (±)-ethyl 3-propanoylbicyclo[2.2.1]hept-5-ene-2-carboxylates 8, 10. a pronounced pref...
We report herein a CuBr-catalyzed three-component coupling of 2-methylbut-3-yn-2-ol, aldehydes and pyrrolidine or 1,2,3,4-tetrahydroisoquinoline leading to the corresponding chiral propargylamines in excellent enantiomeric excess (91 to >99% ee) and high yields (79-95% yield). The dimethylcarbinol unit in 2-methylbut-3-yn-2-ol, which may be easily removed at the later stage to regenerate a term...
Two strategies for the synthesis of the ATP (adenosine triphosphate) analogue ApppI [1-adenosin-5'-yl 3-(3-methylbut-3-enyl)triphosphoric acid diester] (1) are described. ApppI is an active metabolite of the mevalonate pathway and thus is of major biological significance. Chemically synthezised ApppI was purified by using triethylammonium bicarbonate as the counter ion in ion-pair chromatograph...
a variety of group 4 metal catalytic systems (c2-symmetric {ebthi}-, {sbi}-type zirconocene complexes (c2-1–4); c1-symmetric (c1-5–8) and cs-symmetric (cs-9) {cp/flu}-type zirconocene complexes; cp*2zrcl2 (cp* 2-10)), half-metallocene complexes (cpticl3, hm-11), constrained-geometry (cgc-12) titanium catalysts) and post-metallocene catalysts (dow’s ortho-metallated amido-pyridino hafnium comple...
The title mol-ecule, C(13)H(11)Cl(2)N(3)O, is almost planar and adopts a trans conformation with respect to the -N=N- bond; the dihedral angle between the rings is 3.47 (2)°. The N-N bond lengths indicate the presence of single- and double-bond characters and hence the -N=N-NH- moiety. In the crystal, inversion dimers linked by pairs of N-H⋯Cl hydrogen bonds occur, and C-H⋯π and π-π stacking in...
In recent years, there has been an increasing interest in identifying and characterizing the yeast flora associated with diverse types of habitat because of the many potential desirable technological properties of these microorganisms, especially in food applications. In this study, a total of 101 yeast strains were isolated from the skins of tropical fruits collected in several locations in th...
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