نتایج جستجو برای: β azido alcohols
تعداد نتایج: 190437 فیلتر نتایج به سال:
Enolization–aldolization of conjugated ketones, enantioselective synthesis of benzofuryl β-amino alcohols, and synthesis of p-dihydroxyborylphenylalanine (BPA) and its analogs are described. Aldolization of benzaldehyde with lithium dienolates derived from unhindered conjugated cyclohexenones favored anti selectivity, whereas syn selectivity was favored for hindered cyclohexenones. Anti-aldols ...
Disaccharides that contain 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) and d-glycero-d-talo-oct-2-ulosonic acid (Ko) substituted at the 8-position by 4-amino-4-deoxy-β-l-arabinopyranosyl (Ara4N) residues have been prepared. Coupling an N-phenyltrifluoroacetimidate-4-azido-4-deoxy-l-arabinosylglycosyl donor to acetyl-protected allyl glycosides of Kdo and Ko afforded anomeric mixtures of disacchari...
Abstract Borrowing hydrogen (BH) reactions are very useful for the sustainable synthesis of C−C and C−N bonds. They generally operate with transition metal‐based catalysts along stoichiometric/catalytic amounts added base. Here we report that two catalytic transformations, carried out BH methodology, i. e. N ‐alkylation amines alcohols β‐alkylation secondary primary alcohols, can be performed e...
The composition of lipophilic extractives in the cortex and pith of elephant grass ( Pennisetum purpureum Schumach.) stems was thoroughly studied by gas chromatography-mass spectrometry. The predominant compounds were fatty acids followed by sterols (in free and conjugated forms as esters and glycosides). Other steroid compounds, as steroid hydrocarbons and ketones, were also present. Addition...
Abstract A new library of pinane-based 1,4-amino alcohols was synthesised and utilised as chiral ligands in enantioselective diethylzinc addition to benzaldehyde. Aldol condensation (+)-nopinone, derived from (–)-β-pinene, with 2-pyridinecarboxaldehyde gave the key intermediate α,β-unsaturated ketone, which transformed diastereoselective reduction, followed by hydrogenation, resulting alcohols....
Despite the success of potent reverse transcriptase (RT) inhibitors against human immunodeficiency virus type 1 (HIV-1) in combination regimens, the development of drug resistant RTs constitutes a major hurdle for the long-term efficacy of current antiretroviral therapy. Nucleoside β-triphosphate analogs of adenosine and nucleoside reverse transcriptase inhibitors (NRTIs) (3'-azido-2',3'-dideox...
An efficient enantioselective synthesis of lactones was developed based on the catalytic asymmetric conjugate addition (ACA) of alkyl Grignard reagents to pyranones. The use of 2H-pyran-2-one for the first time in the ACA with Grignard reagents allows for a variety of further transformations to access highly versatile building blocks such as β-alkyl substituted aldehydes or β-bromo-γ-alkyl subs...
Abstract Fluorescent probes are valuable tools to visualize non‐catalytic proteins in live cells. Currently, the majority of imaging reagents for based on “always‐on” fluorophores and use these usually necessitate a wash step remove unbounded before microscope imaging. Herein, we report arylamino‐substituted rhodamine as an activatable fluorophore protein We have shown induction arylamino struc...
Phytosterols are a group of steroids alcohols which had been regarded as a functional factor. An unknown compound in phytosterol samples and phytosterol standard samples was detected by HPLC using symmetry C18 column. The quantity of the compound was increased with the enrichment of β-sitosterol. After being collected and analyzed by GC-MS and compared with standard diagram from Wiley and Nist ...
Volatile organic compounds (VOCs), 2-methyl-1-butanol, 3-methyl-1-butanol and 2-phenylethanol, were detected together with β-cyclocitral from the cyanobacterium Microcystis aeruginosa NIES-843. These alcohols were optimally produced after 35 d of culture, during which nitrate nitrogen in the cultured broth became exhausted. Additionally, these alcohols were definitely produced using the 2-keto-...
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