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1.
3 Substitutedisoindolin 1 ones (2 ,3 dihydro 1H isoindolin 1 ones)ofgeneralstructure (1)constitutethekeystructuralfeatureofalargenumberofbioactivemoleculesofnaturalorsyntheticorigin .Forexample ,lennoxamine (2 ) ,1nuevamineandchileninearealkaloidsisolatedfromvarious… 相似文献
2.
Liladhar M. Waykole Joseph J. McKenna Andrew Bach Mahavir Prashad Oljan Repič Thomas J. Blacklock 《合成通讯》2013,43(9):1445-1454
Enantioselective syntheses of (R)‐and (S)‐2‐N‐carbomethoxy‐5‐aminoindanes from (R)‐ and (S)‐phenylalanines, respectively, are described. A Friedel–Crafts reaction employing N‐carbomethoxy phenylalanine leads to chiral 2‐N‐carbomethoxy‐1‐indanone, which is diastereoselectively reduced to 1‐hydroxy‐2‐N‐carbomethoxyindane. After protection of the hydroxyl group, a regioselective nitration gives a 6‐nitroindane intermediate, which upon hydrogenation affords (R)‐or (S)‐2‐N‐carbomethoxy‐5‐aminoindane. 相似文献
3.
Asymmetric Synthesis of (R)‐(−)‐Rhododendrol,the Aglycone of the Hepatoprotective Agent Rhododendrin
Abstract Starting from 2,3‐O‐isopropylidene‐D‐glyceraldehyde (3) as chiral material, (R)‐(?)‐rhododendrol 2, the aglycone of the naturally occurring rhododendrin 1 was synthesized. 相似文献
4.
Three new tail‐to‐tail linked biscalix[6]arenes joined via ether linkages have been synthesized. These bis calix[6]arenes have been characterized by 1H NMR, 13C NMR, and mass spectroscopy and elemental analysis. 相似文献
5.
M. Violante de Paz Ba´ñez Jose´ A. Aznar Moreno 《Journal of carbohydrate chemistry》2013,32(2):120-140
Biodegradable polymers obtained from renewable natural sources are currently receiving increasing attention because they are an alternative to the traditional petroleum‐based plastics. In the present communication we describe the synthesis of the diol monomers 2,3,4‐tri‐O‐benzyl‐L‐arabinitol (ABnOH) and 2,3,4‐tri‐O‐benzylxylitol (XBnOH), and the diamino monomers 1,5‐diamino‐1,5‐dideoxy‐2,3,4‐tri‐O‐benzyl‐L‐arabinitol (ABnNH 2 ) and 1,5‐diamino‐1,5‐dideoxy‐2,3,4‐tri‐O‐benzylxylitol (XBnNH 2 ), which can be used in the preparation of new potentially biodegradable sugar‐based polymers. As an example, we describe the synthesis and characterization of a polyurethane [PU‐(ABnOH‐HMDI)] and a polyurea [PUR‐(ABnNH2‐HMDI)] by poly addition reaction of ABnOH and ABnNH 2 with 1,6‐hexamethylene diisocyanate. 相似文献
6.
Introduction Asarelativelynewmemberofnaturalalkaloidswith2 ,6 disubstituted 3 piperidinolskeleton ,irnigaine 1wasisolatedfromthetubersofArisarumVulgare (Araceae)in1995byMelhaouiandBode .1Itsstructureandrelativeconfigurationswereelucidatedby1HNMRstudiesandtheabsoluteconfigurationwasproposedonthebasisofitsopti calrotation .1Soonafterthen ,Meyerandhisco workersreportedthefirstsynthesisof (- ) (2R ,3R ,6S) irni gaineandtheconfigurationconfirmation .Althoughtheirsynthesisroutewasshortan… 相似文献
7.
XuanJiaPENG XueGongSHE ZiKunWANG WeiGuoQUAN XinFuPAN 《中国化学快报》2005,16(2):186-188
An asymmetric total synthesis of mansonone P and R were achieved, in which introduction of hydroxy substituent at position 2 was performed by Sharpless dihydroxylation of sily enol ether. 相似文献
8.
A simple and effective procedure for the enantioselective synthesis of (R)- and (S)-moprolol was described. The key step was the asymmetric synthesis of enantiopure (R)- and (S)-guaifenesin, which were synthesized from enantioenriched (R)-3-chloro-l,2-propanediol and (S)-epichlorohydrin via kinetics of hydrolysis resolution of racemic epichlorohydrin by chiral Salen-Co^Ⅲ complex. The e.e. values of both the optical compounds were above 98%, and the chemical structures of the target compounds were confirmed by ^1H NMR, ^13C NMR, IR, and MS. 相似文献
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10.
《合成通讯》2013,43(8):1377-1382
Abstract An improved three‐steps method for the conversion of N‐benzyl (S)‐3‐hydroxypyrrolidin‐2‐one 6 to (2S,3S)‐3‐hydroxyproline 1 is reported. The key step is the reductive cyanation of 6. The synthesis of 1 constitutes a formal asymmetric synthesis of (2S,3S)‐3‐hydroxyproline betaines 2. 相似文献
11.
The asymmetric synthesis of (+)‐epi‐cytoxazone, a stereoisomer of potent cytokine modulator cytoxazone, starting from anisaldehyde in six steps, is described. The required configuration was established via Sharpless kinetic resolution followed by the Mitsunobu reaction. 相似文献
12.
HuaWeiLIU YuLinLI 《中国化学快报》2005,16(6):716-718
A concise and efficient total synthesis of (-)-umbelactone 1, an occurring γ-hydroxymethyl-α, β-butenolide from Memycelon umbelatum Burro, is described. The synthesis features the use of a ring closing metathesis strategy. 相似文献
13.
A series of chiral vicinal tertiary diacylamides with C 2‐symmetry was synthesized from (S)‐α‐phenylethylamine, different aromatic aldehydes, and oxalyl chloride. The diacylamides obtained were then reduced to afford chiral vicinal diamines with C 2‐symmetry. We propose that the diacylamides existed in four stable conformational isomers in solution because of the dihedral angle between acylamide bonds. 相似文献
14.
《Journal of carbohydrate chemistry》2013,32(3):209-218
The push‐pull activated methyl (3Z)‐4,6‐O‐benzylidene‐3‐[(methylthio)methylene]‐3‐deoxy‐α‐D‐erythro‐hexopyranosid‐2‐ulose (1) reacted with dialkyl malonate in the presence of potassium carbonate to give the alkyl (2R,4aR,6S,10bS)‐4a,6,8,10b‐tetrahydro‐6‐methoxy‐8‐oxo‐2‐phenyl‐4H‐pyrano[3′,2′:4,5]pyrano[3,2‐d][1,3]dioxine‐9‐carboxylates 2 and 3. Treatment of 1 with 3‐oxo‐N‐phenyl‐butyramide, N‐(4‐methoxy‐phenyl)‐3‐oxo‐butyramide, and 3‐oxo‐N‐o‐tolyl‐butyramide, respectively, in the presence of potassium carbonate and 18‐crown‐6 yielded the (2R,4aR,6S,10bS)‐9‐acetyl‐7‐aryl‐4,4a,7,10b‐tetrahydro‐6‐methoxy‐2‐phenyl[1,3]dioxino‐[4′,5′:5,6]pyrano[3,4‐b]pyridin‐8(6H)‐ones 4–6. (2R,4aR,6S,10bS)‐4,4a,8,10b‐Tetrahydro‐6‐methoxy‐8‐oxo‐2‐phenyl‐4H‐pyrano[3′,2′:4,5]pyrano[3,2‐d][1,3]dioxine‐9‐carboxamide (7) was prepared by anellation reactions of 1 either with malononitrile or with cyanoacetamide. 相似文献
15.
Asymmetric total synthesis of the sex pheromones of Japanese beetle and currant stem girdler, (R)‐japonilure (1) and (4R,9Z)‐9‐octadecen‐4‐olide (2), has been achieved. 相似文献
16.
《Journal of carbohydrate chemistry》2013,32(4-6):353-367
A general route for the preparation of 1,2‐trans‐linked S‐glycosylated amino acid building blocks by a Lewis‐acid‐promoted condensation of peracetylated glycosyl donors and N α‐Fmoc‐Cys‐OH, in good overall yield, is described. In addition, a short and time‐efficient route was applied for the synthesis of N‐glycosylated amino acid building blocks in good overall yields by coupling unprotected glycosylamines and N α‐Fmoc‐Asp(OH)‐O t Bu using TBTU activation. 相似文献
17.
The reaction of various heteroaromatic amino nitriles with diethyl malonate under basic conditions is reported. This reaction affords a series of different highly functionalized 2‐pyridone condensed systems, which can be suitable intermediates in the construction of polyheterocyclic structures. 相似文献
18.
Urethane‐substituted polydiacetylene (PDA) crystals of bis(ethyl)‐urethane of 5,7‐dodecadiyne‐1,12‐diol (poly(ETCD)) with micronscale and nanoscale dimension were fabricated by either ultrasonication, surfactant addition or vapor phase processing approaches. Scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to evaluate the sizes and the shapes of the obtained poly(ETCD) microcrystals. Dynamic light scattering (DLS) was performed to investigate in situ size distributions of these crystals in aqueous suspension. A UV/Visible/NIR Spectrometer (UV/Vis/NIR) was used to study the electronic absorption of the poly(ETCD) microcrystals. Thermochromic phenomena for poly(ETCD) crystals still exist after their dimension was decreased to the nanoscale. 相似文献
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This report describes the synthesis of 4‐substituted‐ and 1,4‐disubstituted‐4‐hydroxypyrrolidin‐2‐ones by cyclization of intermediate γ‐aminoesters prepared from alkylbenzylamines, α‐bromoketones, and lithio ethyl acetate. 相似文献