共查询到19条相似文献,搜索用时 93 毫秒
1.
《高等学校化学学报》1999,20(7):3
(R)-乙基-2-吡啶亚砜与(4R,5R)-二(羟基-二苯基-甲基)-2,2-二甲基-1,3-二氧戊环(TADDOL)可以形成物质的量比为1∶1的手性包结晶体,
X射线衍射分析确定该晶体属单钭晶系, P2 相似文献
2.
3.
以甲酰基二茂铁(1)和手性1,2-二苯基乙二胺[(1R, 2R)-1,2-二苯基乙二胺(2R), (1S,2S)-1,2-二苯基乙二胺(2S)]为原料, 经缩合、还原和N-烷基化反应, 制备了一对新型手性四齿双二茂铁基配体[N,N’-二(二茂铁基甲基)-N,N’-二(2-羟基丙基)-(1R,2R)-1,2-二苯基乙二胺(5R)和N,N’-二(二茂铁基甲基)-N,N’-二(2-羟基丙基)-(1S,2S)-1,2-二苯基乙二胺(5S)]. 用元素分析、红外(IR)、质子核磁共振(1H NMR)、紫外-可见(UV-Vis)、固体圆二色(CD)光谱等对手性产物(3R-5S)进行了表征. 固体CD光谱研究表明, 配体5R(或5S)的手性特征和4R(或4S)相似而与3R(或3S)却有一定差别. 相似文献
4.
以D-阿拉伯糖为原料,依次合成了中间体(2R,3R,4R)-2,3,5-三-O-苄氧基-4-羟基-O-叔丁基二甲基硅基-戊醛肟(3),(2R,3S,4S)-2,3,5-三-O-苄氧基-4-碘-O-叔丁基二甲基硅基-戊醛肟(4)和(2R,3R,4R)-3,4-二-O-苄氧基-2-(苄氧甲基)-3,4-二氢-2H-吡咯-1-醇(5);5与芳基Grignard试剂进行高立体选择性的加成反应制得(2R,3R,4R,5R)-3,4-二-O-苄氧基-2-[4-(苄氧基)苯基)]-5-吡咯-1-醇(6);6经催化氢化合成Radicamine B,总收率18.5%。3和4为新化合物,其结构经1HNMR,MS和元素分析表征。 相似文献
5.
6.
Xi Ying ZHAO Machiko ONO Hiroyuki AKITA Yu Ming CHI 《中国化学快报》2006,17(6):727-729
( )-(4S,5R)-Osmundalactone 1 was isolated from the fungus Paxillus atrotomentosus (Paxillaceae) by Buchanan1. (-)-(4R,5S)-Osmundalactone 1 and ( )-(4R,5S)-5-hydroxy- 2-hexen-4-olide 2 were isolated from Osmunda japonica (Osmundaceae) as feeding inhibitors… 相似文献
7.
《有机化学》2021,(7)
采用溶剂提取法, Diaion HP-20、Sephadex LH-20葡聚糖凝胶、硅胶及制备高效液相等色谱方法,对毛华菊的化学成分进行分离纯化,并利用现代波谱技术对已分离得到的化合物进行结构鉴定.从毛华菊的氯仿部位分离得到4个新化合物,其结构类型属于愈创木内酯衍生物,分别命名为(1S,5R,6S,7S,10S)-愈创木-3,11(13)-二烯-2-酮-12,6-内酯(1)、(1S,5R,6R,7R,8S,10S)-8-异丁酰氧基-愈创木-3,11(13)-二烯-2-酮-12,6-内酯(2)、(1S,5R,6R,7R,8S,10S)-8-(2'-甲基)丁酰氧基-愈创木-3,11(13)-二烯-2-酮-12,6-内酯(3)和(1R,5R,6R,7R,8S,10S,11S)-8-乙酰氧基-愈创木-3-烯-2-酮-12,6-内酯(4),以及2个已知化合物matricarin (5)和11,13-dehydromatricarin (6). 相似文献
8.
以L-谷氨酸和苯甲醛为起始原料,经7步反应合成了重要中间体(2S,5R)-1-苄基-5-(2-羟乙基)吡咯烷-2-羧酸叔丁酯(1),总产率19%;1经TBDMSCl保护羟基后,用10%Pd/C催化氢解去除苄基制得游离胺(2S,5R)-5-(2-二甲基叔丁基硅氧烷基乙基)吡咯烷-2-羧酸叔丁酯(3);3与Boc-β-Cl-ala,在碱性条件下偶合得氯代烃消去产物(2S,5R)-1-[(2-叔丁氧甲酰胺基)丙烯酰基]-5-(2-二甲基叔丁基硅氧烷基乙基)吡咯烷-2-羧酸叔丁酯(4),或在中性条件下偶合得(2S,5R)-1-[(R)-2-叔丁氧甲酰胺基-3-氯丙酰基]-5-(2-二甲基叔丁基硅氧烷基乙基)吡咯烷-2-羧酸叔丁酯(5);4或5经四丁基氟化铵去除TBDMS保护并发生关环反应合成了新型的七元醚环化合物(4R,7S,9R)-4-甲基-4-叔丁氧甲酰胺基-5-羰基-3-氧杂氮杂卓[1,4]并吡咯[1,2-d]-7-羧基叔丁酯(简称6);6于室温在氯仿中静置2 d~3 d自发转换为其构象异构体(4S,7S,9R)-6(简称6’,6/6’=1/9),其结构经1H NMR,13C NMR,2D NMR和HR-ESI-MS表征。 相似文献
9.
以(1S,5S)-(-)-α-蒎烯为原料合成了系列新型(1S,2S,3S,5R)-N-烷基-3-蒎胺类化合物. (-)-α-蒎烯经硼氢化氧化、重铬酸吡啶盐(PDC)氧化得到(1S,2S,5R)-(-)-3-蒎酮; 在BF38226;(C2H5)2O催化下(1S,2S,5R)-(-)-3-蒎酮与伯胺化合物反应生成Schiff碱, 再经KBH4或NaBH4还原得到(1S,2S,3S,5R)-N-烷基-3-蒎胺类化合物. 采用FT-IR, 1H NMR, 13C NMR和GC-MS等分析手段对合成所得(1S,2S,5R)-N-烷基-3-蒎烷亚胺和(1S,2S,3S,5R)-N-烷基-3-蒎胺类化合物的结构进行了表征. 考察了(1S,2S,3S,5R)-N-烷基-3-蒎胺类化合物对大肠杆菌(E. coli)、金黄色葡萄球菌(S. aureus)、枯草芽胞杆菌(B. subtilis)、荧光假单胞菌(P. fluorescens)、白色念珠菌(C. albicans)、黑曲霉(A. niger)和米根霉(R. oryzae)等细菌和真菌的抑菌和杀菌活性. 结果表明(1S,2S,3S,5R)-N-正庚基-3-蒎胺对真菌和细菌均表现出良好的杀菌和抑菌活性. 相似文献
10.
《中国化学快报》1997,(11)
Inthepreviouspapers,wereportedtotalsynthesesofditerpenoidsofC-2oQseriessuchas(+)-podocarpicacid(:),andcalabarbeanalkaloid(-)-physostigmine("from(S)-(-)-2-methyl-2-(2'-nitrovinyl)-5-valerolactone.Herewereportasynthesisofthekeyintermediate(l)for(-)-gibberellinA,=using(R)-(+)-2-methyl-2-(2'-nitrovinyaSachiralbuildingblock.(R)-(+)-2-methyl-2-(2'-nitrovinywassynthesizedaccordingtoliteratUremethod(3)in95%yieldand9l%ee.TheMichaeladditionofbenZylInagnesiumbromideto(R)-nitroolefm2affordedadiastereo… 相似文献
11.
Four new pyrrolidine alkaloids, broussonetines R, S, T, and V and a new pyrroline alkaloid, broussonetine U were isolated from the branches of Broussonetia kazinoki SIEB. (Moraceae) in low yield. Broussonetines R, S and T were formulated as (2R,3R,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(1R)-1-hydroxy-3-[6-(4-hydroxybutyl)-cyclohexy-2-on-1(6)-enyllpropyl] pyrrolidine (1), (2R,3R,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(1R,10S)-1,10,13-trihydroxytridecyl] pyrrolidine (2), (2R,3R,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(1R,5S)-1,5, 13-trihydroxy-10-oxo-tridecyl] pyrrolidine (3). And broussonetines U and V were proposed to be (2S,3S,4S)-2-hydroxymethyl-3, 4-dihydroxy-5-(9-oxo-13-hydroxytridecyl)-5-pyrroline (4), (2R,3S,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(E)-9-oxo-13-hydroxy-3-tridecenyl] pyrrolidine (5), respectively, by spectroscopic and chemical methods. 相似文献
12.
Six new alkaloids, broussonetines W, X, M1, U1, J3, and J2 (1-6) were isolated from the branches of Broussonetia kazinoki SIEB. (Moraceae) as minor constituents. They were formulated as (2R,3R,4R,5R)-2-hydroxy-methyl-3,4-dihydroxy-5-17-(cyclohexy-2-on-1(6)-enyl)heptyllpyrrolidine (1), (2R,3S,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-17-(cyclohexy-2-on-1(6)-enyl)heptyl]pyrrolidine-4-O-beta-D-glucopyranoside (2), (2R,3R,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(9R)-9,13-dihydroxytridecyl]- pyrrolidine (3), (2S,3S,4S)-2-hydroxymethyl-3,4-dihydroxy-5-(10-oxo-13-hydroxytridecyl)-5- pyrroline (4), (2R)-2-[(IS,2S)-1,2-dihydroxy-8-1(2R,3R,4R,5R)-5-(2-hydroxymethyl-3,4-dihydroxy-1-acetylpyrrolidinyl)loctyl]piperidine (5), (2R)-2-[(1S,2S)-1,2-dihydroxy-8-[(2R,3R, 4R,5R)-5-(2-hydroxymethy]-3,4-dihydroxypyrrolidinyl)]octyl]piperidine (6). 相似文献
13.
Two routes from D-glucose to chiral, ring-contracted analogs of the second messenger D-myo-inositol 1,4,5-trisphosphate are described. Methyl alpha-D-glucopyranoside was converted by an improved procedure into methyl 4,6-O-(p-methoxybenzylidene)-alpha-D-glucopyranoside (6) and thence into methyl 2-O-benzyl-3,4-bis-O-(p-methoxybenzyl)-alpha-D-gluco-hexodialdopyranoside (1,5) (14) in four steps. In the first ring-contraction method 14 was converted into methyl 2-O-benzyl-6,7-dideoxy-3,4-bis-O-(p-methoxybenzyl)-alpha-D-gluco-hept-6-enopyranoside (1,5) (15), which on sequential treatment with Cp(2)Zr(n-Bu)(2) followed by BF(3).Et(2)O afforded a mixture of (1R,2S,3S,4R,5S)-3-(benzyloxy)-4-hydroxy-1,2-bis[(p-methoxybenzyl)oxy]-5-vinylcyclopentane (16) and its 4S,5R diastereoisomer 17. Removal of the p-methoxybenzyl groups of 16 and subsequent phosphorylation and deprotection afforded the first target compound, (1R,2R,3S,4R,5S)-3-hydroxy-1,2,4-tris(phosphonooxy)-5-vinylcyclopentane (3). In the second route, intermediate 14 was subjected to SmI(2)-mediated ring contraction to give (1R,2S,3S,4R,5S)-3-(benzyloxy)-4-hydroxy-5-(hydroxymethyl)-1,2-bis[(p-methoxybenzyl)oxy]cyclopentane (20). Benzylation of 20 provided (1R,2S,3S,4R,5S)-3-(benzyloxy)-6-[(benzyloxy)methyl]-4-hydroxy-1,2-bis[(p-methoxybenzyl)oxy]cyclopentane (22) and (1R,2S,3S,4R,5S)-3,4-bis(benzyloxy)-5-(hydroxymethyl)-1,2-bis[(p-methoxybenzyl)oxy]cyclopentane (21), which were elaborated to the target trisphosphates (1R,2R,3S,4R,5S)-3-hydroxy-5-(hydroxymethyl)-1,2,4-tris(phosphonooxy)cyclopentane (4) and (1R,2S,3R,4R,5S)-1,2-dihydroxy-3,4-bis(phosphonooxy)-5-[(phosphonooxy)methyl]cyclopentane (5), respectively. Both 3 and 4 mobilized intracellular Ca(2+), but 4 was only a few fold less potent than D-myo-inositol 1,4,5-trisphosphate, demonstrating that effective mimics can be designed that do not bear a six-membered ring. 相似文献
14.
Marin J Didierjean C Aubry A Briand JP Guichard G 《The Journal of organic chemistry》2002,67(24):8440-8449
The synthesis of (2S,5R)-5-hydroxy-6-oxo-1,2-piperidinedicarboxylates (5) and related (3S,6R)-3-hydroxy-6-alkyl-2-oxo-1-piperidinecarboxylates has been developed. The approach is based on the asymmetric hydroxylation of enolates generated from the corresponding N-protected-6-substituted piperidin-2-ones. The utility of 5a as a precursor in the synthesis of (2S,5R)-5-hydroxylysine (1), an amino acid unique to collagen and collagen-like proteins, has also been demonstrated. (2S)-6-oxo-1,2-piperidinedicarboxylates (6) required for hydroxylation studies were prepared in 38-74% yield, starting from conveniently protected aspartic acid as inexpensive chiral adduct. Hydroxylation of 6 to 5 proceeds in high yield and excellent diastereoselectivity by treatment of their Li-enolate with (+)-camphorsulfonyloxaziridine at -78 degrees C. Ring opening of di-tert-butyl (2S,5R)-6-oxo-1,2-piperidinedicarboxylate ((5R)-5a) under reductive conditions afforded the corresponding 1,2-diol (17) in 91%, which was further transformed to (2S,5R)-5-hydroxylysine in four steps (84%). 17 is also a versatile intermediate in the preparation of tert-butyl (2S,5R)-2-[(tert-butoxycarbonyl)amino]-5-hydroxy-6-iodohexanoate (3) and tert-butyl (2S)-2-[(tert-butoxycarbonyl)amino]-4-[(2R)-oxiranyl]butanoate (4), two amino acid derivatives used in the total synthesis of the bone collagen cross-link (+)-pyridinoline (2a). 相似文献
15.
Tamura O Gotanda K Yoshino J Morita Y Terashima R Kikuchi M Miyawaki T Mita N Yamashita M Ishibashi H Sakamoto M 《The Journal of organic chemistry》2000,65(25):8544-8551
Optically pure (5R)- [and (5S)]-5,6-dihydro-5-phenyl-2H-1, 4-oxazin-2-one N-oxides [(5R)- and (5S)-2] were designed as chiral (E)-geometry-fixed alpha-alkoxycarbonylnitrones 1. The nitrones (5R)- and (5S)-2 were synthesized by three-step oxidation of (R)- and (S)-phenylglycinols [(R)- and (S)-3], condensation of the resulting (R)- and (S)-2-hydroxylamino-2-phenylethanols [(R)- and (S)-5] with glyoxylic acid, and cyclization of the intermediary nitrones (R)- and (S)-6b. The nitrone (5R)-2reacted with olefins 7-14 under mild conditions to afford the corresponding cycloadducts 15-22 as the main products via the least sterically demanding exo modes. Cycloadduct 30 obtained from (5S)-2 and cyclopentadiene was effectively elaborated to (1S,4S, 5R)-4-benzyloxycarbonylamino-2-oxabicyclo[3.3.0]oct-7-en-3-one (28), the key synthetic intermediate of carbocyclic polyoxin C. 相似文献
16.
Yanagi T Kitajima A Anzai K Kodama K Mizoguchi J Fujiwara H Sakiyama H Kamoda O Kamei C 《Chemical & pharmaceutical bulletin》1999,47(11):1650-1654
Of 4-amino-5-chloro-2-methoxy-N-(1-ethyl-2-hydroxymethyl-4- pyrrolidinyl)benzamide, four optical isomers, (2S,4S)-1 (TKS159), (2S,4R)-25, (2R,4S)-26 and (2R,4R)-27, were prepared from optically active 4-amino-1-ethyl-2-hydroxymethylpyrrolidine di-p-toluenesulfonate [(2S,4S)-14, (2S,4R)-17, (2R,4S)-20 and (2R,4R)-23, respectively]. The requisites, (2S,4S)-14, (2S,4R)-17, (2R,4S)-20 and (2R,4R)-23, were prepared from a commercially available trans-4-hydroxy-L-proline. The absolute configurations of (2S,4S)-1 (TKS159), (2S,4R)-25, (2R,4S)-26 and (2R,4R)-27 were spectroscopically determined. Of the benzamide derivatives, four optical isomers, (2S,4S)-1, (2S,4R)-25, (2R,4S)-26 and (2R,4R)-27, showed a relatively potent affinity for 5-hydroxytryptamine 4 (5-HT4) receptors in a radioligand binding assay ([3H]GR113808). The activities of 25-27 were less effective than that of 1 for the gastric emptying of a phenol red semisolid meal in rats. All this suggests that the most potent of the isomers was 4-amino-5-chloro-2-methoxy-N-[(2S,4S)-1-ethyl-2- hydroxymethyl-4-pyrrolidinyl]benzamide (1). 相似文献
17.
Shibano M Tsukamoto D Fujimoto R Masui Y Sugimoto H Kusano G 《Chemical & pharmaceutical bulletin》2000,48(9):1281-1285
Four new pyrrolidine alkaloids, broussonetines M, O, P, and Q, were isolated from the branches of Broussonetia kazinoki SIEB, (Moraceae). Broussonetines M, O, P, and Q were formulated as (2R,3R,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(10S)-10,13-dihydroxy-tri decyl]pyrrolidine (1), (2R,3R,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(E)9-oxo-13-hydroxy-3- tridecenyl]pyrrolidine (2), (2R,3R,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(E)10-oxo-13-hydroxy-3-++ +tridecenyl]pyrrolidine (3), and (2R,3S,4R,5R)-2-hydroxymethyl-3-hydroxy-4-(beta-D-glucopyranosyloxy++ +)-5-[10-oxo-13-(beta-D-glucopyranosyloxy)tridecyl]pyrrolidine (4) respectively, by spectroscopic and chemical methods. 1-4 inhibited beta-glucosidase, beta-galactosidase and beta-mannosidase. 相似文献
18.
[reaction: see text] (3R,5R)-1 R1 & R2 = TBDPS, (3S,5R)-2 R1 = Bn,R2 = TBDPS, (3S,5S)-3 R2 & R2 = Bn. trans-3,5-Bis(benzyl/tert-butyldiphenylsilyloxymethyl)morpholines, promising candidates for the C(2)-symmetric class of chiral reagents, were prepared with excellent optical purity. A key step in the synthesis is the coupling of a serinol derivative with 2,3-O-isopropylideneglycerol triflate or its equivalent. This methodology was extended to the synthesis of chiral trans-3-(benzyloxymethyl)-5-(tert-butyldiphenylsilyloxymethyl)morpholine, a potentially useful chiral building block. 相似文献
19.
Urones JG Garrido NM Díez D El Hammoumi MM Dominguez SH Antonio Casaseca J Davies SG Smith AD 《Organic & biomolecular chemistry》2004,2(3):364-372
The stereoisomers of 2-amino-5-carboxymethyl-cyclopentane-1-carboxylate may be prepared stereoselectively from diester derivatives of (E,E)-octa-2,6-diendioc acid, with the key step utilising the conjugate addition of homochiral lithium N-benzyl-N- alpha-methylbenzylamide. The trans-C(1)-C(2)-stereoisomers are readily prepared via a diastereoselective tandem conjugate addition cyclisation protocol with lithium (R)-N-benzyl-N- alpha-methylbenzylamide, with subsequent hydrogenolysis and ester hydrolysis giving the (1R,2R,5R)- and (1R,2R,5S)- beta-amino diacids in good yields. The preparation of the cis-C(1)-C(2)-stereoisomers utilises a protocol involving N-oxidation and Cope elimination of the major diastereoisomeric product arising from conjugate addition and cyclisation, giving homochiral (R)-5-carboxymethyl-cyclopentene-1-carboxylate. Conjugate addition of either lithium (R)- or (S)-N-benzyl-N- alpha-methylbenzylamide to (R)-5-carboxymethyl-cyclopentene-1-carboxylate, and diastereoselective protonation with 2,6-di-tert-butyl phenol gives, after hydrogenolysis and ester hydrolysis, the (1S,2R,5R)- and (1R,2S,5R)- beta-amino diacids in good yield. The use of (S)-N-benzyl-N- alpha-methylbenzylamide in the initial conjugate addition and cyclisation reaction, and subsequent repetition of the elimination and conjugate addition strategy allows stereoselective access to all stereoisomers of 2-amino-5-carboxymethyl-cyclopentane-1-carboxylate. 相似文献