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1.
以茴香醛保护氨基方法得到的β-构型的四乙酰基氨基葡萄糖盐酸盐(1)为原料, 采用三氯乙酰基(TCA)、三氯乙酰亚胺酯基(TCI)和乙硫基(SEt)保护体系, 经五步反应以产率40.5%得到完全β-构型保护的β-(1→3)-2-脱氧-2-氨基葡二糖7, 又经两步合成得到保护的β-(1→3)-2-脱氧-2-氨基葡二糖受体8, 共八步合成了保护的β-(1→3)-2-脱氧-2-氨基葡三糖10, 总产率为27%. 以上化合物均为未知. 同时, 还得到了用以合成β-(1→4)-保护的氨基葡四糖的受体6. 采用该保护体系可以高选择性地、较高产率地合成氨基寡糖. 相似文献
2.
The direct regioselective benzylation of p-methoxyphenyl 2-deoxy-2-phthalimido-β-D-glucopyranoside (1) with benzyl bromide under basic conditions gives 4,6-di-O-benzyl (2a), 4-O-benzyl (3a) and 6-O -benzyl-2-deoxy-2-phthalimido-β-D-glucopyranoside 4a. When the benzylation was performed in the presence of di-n-butyltin oxide, p-methoxyphenyl 4,6-di-O-benzyl-2-deoxy-2-phthalimido-β-D-glucopyranoside 5 was obtained in high yield. This constitutes a new and efficient one-pot procedure for the synthesis of the glycosyl acceptor 5. 相似文献
3.
3-Cyclohex-2-enyl-4-hydroxy-1-methylquinolin-2(1H)-one (5) reacts with pyridine hydrotribromide in CH2Cl2 at 0–5°C for 0.75h to give a furo fused heterocycle 6 in 96% yield. Product 6 on treatment with KOH-EtOH eliminates HBr to give compound 8 which on treatement with Pd-C in refluxing diphenyl ether for 0.5h furnishes benzofuro[3,2-c]quinolone 9 in 90% yield. Substrate 5 on sequential treatment with Ac2O-AcONa and Br2/AcOH followed by KOH-EtOH, however produces bicyclic product 7 in excllent overall yield. Substrate 5 reacts with 1 equivalent of m-chloroperbenzoic acid in refluxing benzene to furnish bicyclic heterocycle 12 in 80% yield and with cold conc. H2SO4 at 0–5°C for 2h generates the bicyclic heterocycle 14 in 90% yield. 相似文献
4.
Alexander Wiatschka Karl-Hans Ongania 《Monatshefte für Chemie / Chemical Monthly》1982,113(5):593-602
TheN-arylthioformimidates4 a-e, which may be obtained byS-alkylation of the thioformanilides3 a-e, react with chloroacetylchloride/triethylamine to yield the (3R,4S/3S,4R)-1-aryl-3-chloro-4-methylthio-2-azetidinones5 a-e and the formanilides6 a-e. Dehalogenation of5 b-e with tri-n-butyltinhydride yield the title compounds7 b-e. Hydrogenolysis of7 b and7 c yields7 f and7 g. 相似文献
5.
Abstract D-Erythorbate 2-phosphate (3) was prepared by phos phorylation of 5, 6-0-isopropylidene-D-erythorbate (5) with phosphoryl chloride at high pH in the presence of pyridine. Following removal of the 5, 6-acetal, a crude magnesium salt of 3 was isolated in 67–71% yield. The salt contained 74% of 3, 9% of D-erythorbate 2-diphosphate (7), and 5% of bis-(D-erythorbyl) 2, 2′-phosphate (6). Analytically pure 3 was obtained as its crystalline magnesium and tricyclohexyl-ammonium salts in 26 and 47% yields, respectively, from 5. 相似文献
6.
7.
From the reaction of Ru(CO)5 and Pt(COD)2, COD = 1, 5-cyclooctadiene, the new platinum-ruthenium heteronuclear cluster complex Pt2Ru4(CO)18,1, was obtained in 60% yield.1 has a folded ladder-like structure with alternating pairs of ruthenium atoms and platinum atoms. The cluster of1 can be split to yield the known compound PtRu2(CO)8(2-dppe),2, (54% yield) by reaction with 1, 2-bis(diphenylphosphino)ethane, dppe, at 25°C. When1 was treated with excess dppe at 40°C, thebis-diphos compound3, PtRu2(CO)6(-2-dppe)2 was obtained (39% yield). Under the similar reaction conditions,2 was converted to3 in 44% yield. All these complexes were characterized by single crystal X-ray diffraction analyses. Compounds2 and3 both contain a triangular cluster of one platinum and two ruthenium atoms, but in2 the bidentate ligand, dppe, chelates the platinum atom and in3 the two dppe ligands bridge the two Pt-Ru metal-metal bonds. Crystal data for1: space group C2/c,a=12.542(2)Å,b=15.350(4)Å,c=15.252(3)Å, =105.32(2)°,Z=4, 2192 reflections,R=0.025. For2: space group P21/c,a=14.351(2)Å,b=13.486(3)Å,c=19.218(3)Å, =108.48(1)°,Z=4, 3029 reflections,R=0.027. For3: space group P21/c,a=18.836(6)Å,b=15.559(5)Å,c=23.259(7)Å, =111.26(2)°,Z=4, 4204 reflections,R=0.038. 相似文献
8.
Summary The title compounds were prepared as follows:tert.-butyl-indane (10) was formylated to give a 72:28 mixture of the aldehydes23a and23b which were submitted to aKnoevenagel-Doebner condensation to afford the cinnamonic acids24. From the mixture, the pure stereoisomer24a was obtained by one crystallization in 57% yield. Its methylester27a could be quantitatively dealkylated to the methylester8 by treatment with AlCl3 in toluene. Cyclization to the indanone9 was then performedvia the propionic acid7 with polyphosphoric acid in 95% yield. From9 the carboxymethyl derivative30 was obtained by treatment with dimethylcarbonate and NaH. The second synthone 4-chlormethyl-indane (19) was prepared from the corresponding alcohol18 (in 82% yield) which in turn could be obtained from methylester17 by reduction with LiAlH4. The latter was accessible in 75% yield by dealkylation of ester13.
Herrn Prof. Dr.K. Kratzl mit besten Wünschen zum 80. Geburtstag gewidmet 相似文献
9.
《Journal of Coordination Chemistry》2012,65(2):253-260
Abstract The reaction of an ethanolic suspension of [NH4]2[IrCl6] and P-t-Bu2Me, in the presence of HCl for 15h gives [HP-t-Bu2Me][Ir2Cl7(P-t-Bu2Me)2], 1, in 13.5% yield. The dinuclear complex 1 was characterized by elemental analyses, IR, 1H, 31P NMR spectroscopy, and single crystal X-ray analysis. However, when the above reaction is continued for 48 h one obtains only [Ir(H)(Cl)2(P-t-Bu2Me)2], 2, in good yield. It is proposed that complex 1 is a reaction intermediate to 2. Crystallographic data for 1 (at 298 K): a = 16.151(3) Å, b = 11.885(2)Å, c = 21.665(4) Å, β = 90.26(2)°, space group P21/c (Z=4). 相似文献
10.
Xue-Long Sun Toshitsugu Kai Hiroalu Takayanagi Kmio Furuhata 《Journal of carbohydrate chemistry》2013,32(4-5):541-547
Abstract Methyl 4,5,7,8,9-penta-O-acetyl-2,6-anhydro-3-deoxy-D-glycero-D-galacto-enonate (5) was synthesized from KDN methyl ester 2 with a catalytic amount of concentrated sulfuric acid in acetic anhydride, or from 2-chloro-KDN methyl ester 4 with DBU in good yield. Hydrogenation of 4 and 5 with 10% Pd-C gave 2-deoxy-2-Hax-KDN 8 and 2-deoxy-2-Heq-KDN derivative 11 in high yield, respectively. The structures of these compounds were elucidated from the MS, elemental analysis, 1H NMR and 13C NMR data. 相似文献
11.
Noureddine Raouafi Khaled Boujlel Mohamed Lamine Benkhoud 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2471-2482
N-(-1H-Benzimidazol-2-yl) imidates 1a–c react with chlorophosphoramide to give the N-[-1-N,N,N′,N′-tetramethylphosphoramidoyl-1H-benzimidazol-2-yl]-imidates 2a–c or with dichlorophosphoramide to yield the bis[(N-1-benzimidazol-2-yl)-imidate] phosphoramide derivatives 3a–b. The reaction of compounds 2a–c toward primary amines is studied. The obtained amidine derivatives 4a–b were unambiguously characterized by different spectroscopic techniques (IR, 1H, 13C, and 31P NMR, and in some cases MS). 相似文献
12.
Rolf Carlson Alexandre Descomps Alemayehu Mekonnen Andreas Westerlund Martina Havelkova 《合成通讯》2013,43(19):2939-2945
A convenient procedure for the synthesis of 1-bromo-3-buten-2-one, 4, from commercially available 2-ethyl-2-methyl-1,3-dioxolane, 1, is described. The procedure involves three reaction steps: (1) The acetal 1 is converted to 2-(1-bromoethyl)-2-bromomethyl-1,3-dioxolane, 2, by reacting 1 with elemental bromine in dichloromethane to yield 98% of 2. (2) Dehydrobromination of 2 with potassium tert-butoxide in tetrahydrofuran gives 2-bromomethyl-2-vinyl-1,3-dioxolane, 3, in 84–93% yield. (3) Removal of the acetal protection from 3 by formolysis for 6–10 h afforded 1-bromo-3-buten-2-one, 4, in 85–94% yield. A more rapid method is acid hydrolysis of 3 under microwave activation (100 °C, 8–10 min), by which 4 was obtained in 75% yield. Full experimental details are given.
13.
Karl-Hans Ongania Ulrike Schwarzenbrunner Karin Humer 《Monatshefte für Chemie / Chemical Monthly》1984,115(2):215-222
The thioformimidates4, which may be obtained by S-alkylation of the thioformamides3, react with chloroacetylchloride/triethylamine to yield the (3R, 4S/3S, 4R)-3-chloro-4-methylthio-2-azetidinones5. Dehalogenation of5 leads to6, which undergoes ring closure by the action of mercuric oxide. Treatment of8, which may be synthesized by chlorolysis of7, with triethylamine gives also the title compounds9. 相似文献
14.
Stereoselective diazotization of (S)-2-amino-2-phenyl acetic acid (L-phenyl glycine) (4) with NaNO2 in 6% H2SO4 in a mixture of acetone and water gave optically pure (S)-2-hydroxy-2-phenyl acetic acid (L-mandelic acid) (5). Esterification, gave (S)-2-hydroxy-2-phenyl acetic acid esters (6). The latter was treated with chloroacetyl chloride in the presence of triethylamine (TEA) in dichloromethane (DCM) to yield (S)-2-chloroacetyloxy phenyl acetic acid ester (2). In another sequence, the reaction of 2-(chloromethyl)-3-arylquinazolin-4(3H)-one (9) treated with N-Boc piperazine, followed by deprotection of the Boc group, to obtain 3-aryl-2-((piperazin-1-yl)methyl) quinazolin-4(3H)-one (3). Reaction of 2 with 3 in the presence of K2CO3 and KI gave the title compound, 2-(2-(4-((3,4-dihydro-4-oxo-3-arylquinazolin-2-yl)methyl)piperazin-1-yl) acetoyloxy)-2-phenyl acetic acid esters (1). The structures of all the new compounds obtained in the present work are supported by spectral and analytical data. 相似文献
15.
F. Asinger D. Neuray A. Saus J. Gräber U. Lames 《Monatshefte für Chemie / Chemical Monthly》1972,103(2):406-417
Zusammenfassung Aliphatische Amine bzw. Alkohole reagiren (in Gegenwart von PbO) mit 2-Methyl-2,5-diphenyl-imidazolin-4-thion (1) glatt zu 4-Alkylamino-2H-imidazolen (2 a-f, 7) bzw. 4-Alkoxy-2H-imidazolen (9 a-g). Die Darstellung von 4-Arylamino-2H-imidazolen (4 a-j) bzw. 4-Aroxy-2H-imidazolen (10 a-t) gelingt in guten Ausbeuten durch Umsetzung von 2-Methyl-2,5-diphenyl-4-chlor-2H-imidazol (3) mit aromatischen Aminen in siedenden Lösungsmitteln (Petroläther, Aceton) bzw. mit Phenolen in siedendem Aceton in Gegenwart von HCl-Acceptoren (K2CO3, Dabco). Die Umsetzung von3 mit Anthranilsäure liefert in 83proz. Ausbeute 1-Methyl-1,3-diphenyl-1H, 9H-imidazo[5,1-b]chinazolin-9-on (6). Aus3 und Thiophenol erhält man glatt 2-Methyl-2,5-diphenyl-4-phenylthio-2H-imidazol (11).
Herrn Prof. Dipl.-Ing., Dr. techn., Dr. e. h.Otto Kratky zum 70. Geburtstag herzlichst gewidmet.
Teil der DiplomarbeitJ. Gräber, Techn. Hochschule Aachen, 1970.
Teil der DiplomarbeitU. Lames, Techn. Hochschule Aachen, 1971. 相似文献
On the reaction of 2-Methyl-2,5-diphenyl-imidazoline-4-thione and 2-Methyl-2,5-diphenyl-4-chloro-2H-imidazole with aliphatic and aromatic amines, alcohols and phenols (joint action of elemental sulfur and gaseous ammonia upon ketones, LXXVI
Aliphatic amines and alcohols (in the presence of PbO) easily react with 2-methyl-2.5-diphenyl-imidazoline-4-thione (1) to 4-alkylamino-2H-imidazoles (2 a-f, 7) and 4-alkoxy-2H-imidazoles (9 a-g), resp. 4-arylamino-2H-imidazoles (4 a-j) are prepared in good yields by the reaction of 2-methyl-2.5-diphenyl-4-chloro-2H-imidazole (3) with aromatic amines under reflux in light naphtha or acetone; in the same manner 4-aroxy-2H-imidazoles (10 a-t) are obtained from3 and phenols in boiling acetone in the presence of HCl-acceptors (K2CO3, Dabco). Reaction of3 with anthranilic acid leads to1-methyl-1.3-diphenyl-1H.9H-imidazo[5.1-b]chinazoline-9-one (6) in 83% yield. By reaction of thiophenol with3 2-methyl-2.5-diphenyl-4-phenylthio-2H-imidazole (11) is easily obtained.
Herrn Prof. Dipl.-Ing., Dr. techn., Dr. e. h.Otto Kratky zum 70. Geburtstag herzlichst gewidmet.
Teil der DiplomarbeitJ. Gräber, Techn. Hochschule Aachen, 1970.
Teil der DiplomarbeitU. Lames, Techn. Hochschule Aachen, 1971. 相似文献
16.
Abstract A facile procedure is presented for the synthesis of (E)-1-(3′-hydroxy-2′-furanyl)-3-(3″-hydroxy-4″-methoxyphenyl)-2- propen-1-one (6). Galactosylisomaltol (1) was condensed with isovanillin (2) under strong alkaline conditions at 25 [ddot]C to form (E)-1-(3′-O-β-D-galactopyranosyloxy-2′-furanyl)-3-(3″- hydroxy-4″-methoxyphenyl)-2-propen-1-one (4). (E)-1-(3′-hydroxy-2′-furanyl)-3-(3″-hydroxy-4″-methoxyphenyl)-2-propen-1-one (6) was obtained by acid hydrolysis of 4 in a 53.9% yield. This hetero-cyclic 2-propen-1-one was characterized on the basis of spectral data (IR and 1H NMR), physicochemical properties, and conversion to a mono-O-acetyl derivative. 相似文献
17.
18.
(S)‐(+)‐3‐Octanol (S)‐1 was prepared in high enantiomeric excess through catalyzed acetylation of racemic alcohol 1 by using lipase from Candida antarctica (Chirazyme L‐2) in the presence of vinyl acetate in toluene at 30°C. The pure (S)‐1 was obtained in 73% isolated yield with 62% conversion. Moreover, acetate (R)‐2 was converted to (S)‐1 via mesylation and followed by hydrolysis using sodium bicarbonate solution in 44% yield. 相似文献
19.
K. Gewald U. Hain R. Schindler M. Gruner 《Monatshefte für Chemie / Chemical Monthly》1994,125(10):1129-1143
Summary 6-Amino-thiazolo[4,5-c]isothiazole derivatives4 are obtained by addition of hydrogen sulfide to the 4-Amino-thiazoline-5-carbonitrile2 followed by cyclooxidation of the intermediate thioamides3. In the presence of sodium sulfite the hydrolysis of the4-amino-2-methylthio-thiazolium salts5 derived from the title compounds1 yields the4-amino-thiazolin-2-ones6. By their further hydrolysis the 2,4-dioxo-thiazolidin-5-carboxamides8 are formed. The 2-oxo-and 2-thioxo-thiazolo [4,5-d]pyrimidin-7-ones and -thiones available from1 undergo ring opening by hydrolysis to give the substituted 4-amino-6-oxo- and 4-amino-6-thioxo-pyrimidine-5-thiols15a–h and13i–e. They have been isolated as their disulfides14 or 5-alkyl derivativesi.e. the substituted 4-amino-5-alkylthiopyrimidin-6-ones and -thiones16. In analogy, the intermediate 6-amino-7-oxo-thiazolo[4,5-d] pyrimidin-2-thione18 and the 7-amino-thiazolo[4,5-d]-pyrimidin-2-thione24 derived from1 react by ring cleveage to yield the 1,4-and 4,6-diamino-pyrimidin-5-thiole derivatives22 and27, respectively, isolated as their disulfides or alkylthio-derivatives. From the pyrimidine16b the pyrimido[5,4-b]1,4-thiazine derivative18 can be obtained. 相似文献
20.
Summary The hetero-Diels-Alder reaction of 3-aryl-2-benzoyl-2-propenenitriles1a–d with enol ethers2a–c yieldscis/trans diastereoisomers of 2-alkoxy-4,6-diaryl-3,4-dihydro-2H-pyran-5-carbonitriles3 and4 in 79–98% yield. The similar reaction of1a–c with cyclic enol ether5 affords diastereoisomeric cycloadducts6 and7 withcis annulated pyran rings. Reaction of3 with sulfuric acid leads to 2-hydroxy-3,4-dihydro-2H-pyran-5-carbonitriles8 and9.
Hetero-Diels-Alder-Reaktion von 3-Aryl-2-benzoyl-2-propennitrilen mit Enolethern. Synthese von 2-Alkoxy-3,4-dihydro-2H-pyran-5-nitrilen
Zusammenfassung Die Hetero-Diels-Alder-Reaktion der 3-Aryl-2-benzoyl-2-propennitrile1a–d mit den Enolethern2a–c ergibt diecis/trans-diastereomeren 2-Alkoxy-4,6-diaryl-3,4-dihydro-2H-pyran-5-nitrile3 und4 in einer Ausbeute von 79–98%. Dieselbe Reaktion von1a–c mit dem cyclischen Enolether5 liefert die diastereomeren Cycloaddukte6 und7 mitcis-anellierten Pyranringen. Reaktion von3 mit Schwefelsäure führt zu den 2-Hydroxy-3,4-dihydro-2H-pyran-5-nitrilen8 und9.相似文献