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(S)-和(R)-盐酸氟西汀的不对称合成 总被引:2,自引:0,他引:2
盐酸氟西汀是一种临床广泛使用的非三环类抗抑郁药, 本工作介绍了一种不对称合成(S)-和(R)-盐酸氟西汀的方法. 以自制的手性噁唑硼烷为催化剂, 将起始原料β-氯苯丙酮不对称催化氢化还原成(S)-或(R)-手性醇, 这一步的化学收率和光学收率都较高. 然后再经两步, (S)-和(R)-手性醇转化为(S)-和(R)-盐酸氟西汀. 整个工艺只需三步, 总收率为66.5%, 盐酸氟西汀对映体的ee值可达98.6%. 还考察了反应温度、溶剂、催化剂的量等因素对β-氯苯丙酮的不对称氢化还原的化学产率和光学收率的影响. 相似文献
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手性螺硼酸酯(R)-或(S)-1,1'-联-2-萘酚硼酸-(S)-脯氨酸酐[(R,S)-1或(S,S)-1]对前手性亚胺硼烷还原的不对称催化活性被观察到.在(R,S)-1或(S,S)-1存在下,由前手性二烷基酮或烷基苯酮与苯胺缩合生成的前手性亚胺在THF中被硼烷还原,高产率地给出手性仲胺,其对映体纯度高达74% ee.其中,三种手性仲胺[N-(2-戊基)苯胺,N-(3-甲基-2-丁基)苯胺和N-(4-甲基-2-戊基)苯胺]系首次合成. 相似文献
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(S)-和(R)-普萘洛尔的不对称合成 总被引:3,自引:0,他引:3
普萘洛尔是一种临床上广泛使用的β受体阻断剂, 介绍了一种不对称合成(S)-和(R)-普萘洛尔的方法. 以手性Salen-CoIII催化剂水解动力学拆分外消旋环氧氯丙烷得到高光学纯度的(S)-环氧氯丙烷和(R)-3-氯-1,2-丙二醇, 以(S)-环氧氯丙烷为手性原料先水解得(S)-3-氯-1,2-丙二醇, 其与1-萘酚反应得(S)-3-(1-萘基)-丙烷-1,2-二醇, 再与氯化亚砜反应得环状亚硫酸酯, 最后和异丙胺作用得(S)-普萘洛尔, 总收率80.9%, 光学纯度大于99%; 而同样以(S)-环氧氯丙烷为手性原料直接与1-萘酚反应得(2R)-3-(1-萘氧基)-1,2-环氧丙烷, 再与异丙胺作用得(R)-普萘洛尔, 总收率74.5%, 光学纯度大于99%. 相似文献
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首次利用甾体皂甙元氧化降解废弃物(R)-4-甲基-δ-戊内酯合成了松叶蜂性信息素(2S,3S,7S)-3,7-二甲基-2-十五醇乙酸酯(2)和丙酸酯(3). 甾体皂甙元氧化降解废弃物(R)-4-甲基-δ-戊内酯首先被转化成为性质稳定易保存的(R)-5-溴-4-甲基戊酸甲酯(5), 化合物5经过偶联、还原、溴代、环氧加成开环和酰化反应给出目标分子. 本研究结果不仅为松叶蜂性信息素化合物2和3提供了一个简洁有效的合成方法, 同时也丰富了资源化学(即基于资源性化合物合理利用的有机合成化学)的内涵. 相似文献
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The reduction of prochiral ketones using chiral reducing reagents, prepared from lithium aluminum hydride and (-)-(1R, 2S, 3S, 5R)-10-anilinopinanediol (5) and (-)-(1R, 2S, 3S, 5R)-10-N-methylanilinopinanediol (6), affords chiral secondary alcohols in useful chemical yields (70 ~ 93%) but in low optical purity (8 ~ 33% ee). Modifiers 5 and 6 are synthesized from (lR)-(-)-β-pinene in three steps. 相似文献
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Photochemical Reaction of Optically Active 2-(1′-Methylallyl)anilines with Methanol It is shown that (?)-(S)-2-(1′-methylallyl)aniline ((?)-(S)- 4 ) on irradiation in methanol yields (?)-(2S, 3R)-2, 3-dimethylindoline ((?)-trans- 8 ), (?)-(1′R, 2′R)-2-(2′-methoxy-1′-methylpropyl)aniline ((?)-erythro- 9 ) as well as racemic (1′RS, 2′SR)-2-(2′-methoxy-1′-methylpropyl) aniline ((±)-threo- 9 ) in 27.1, 36.4 and 15.7% yield, respectively (see Scheme 3). By deamination and chemical correlation with (+)-(2R, 3R)-3-phenyl-2-butanol ((+)-erythro- 13 ; see Scheme 4) it was found that (?)-erythro- 9 has the same absolute configuration and optical purity as the starting material (?)-(S)- 4 . Comparable results are obtained when (?)-(S)-N-methyl-2-(1′-methylallyl)aniline ((?)-(S)- 7 ) is irradiated in methanol, i.e. the optically active indoline (+)-trans- 10 and the methanol addition product (?)-erythro- 11 along with its racemic threo-isomer are formed (cf. Scheme 3). These findings demonstrate that the methanol addition products arise from stereospecific, methanol-induced ring opening of intermediate, chiral trans, -(→(?)-erythro-compounds) and achiral cis-spiro [2.5]octa-4,6-dien-8-imines (→(±)-threo-compounds; see Schemes 1 and 2). 相似文献
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Anastasy О. Kolodiazhna Аleksei I. Skliarov Alena A. Slastennikova 《Phosphorus, sulfur, and silicon and the related elements》2020,195(9):713-717
AbstractAn asymmetric synthesis of (+)- and (–)-methiine (S-methyl-(R)-cysteine sulfoxide) diastereomers has been developed. These natural sulfur compounds were isolated from a variety of Brassica vegetables. As the starting compound, (R)-cysteine was used, which was methylated to form (R)-S-methylcysteine. Then the oxidation of S-methylcysteine with tert-butyl hydroperoxide catalyzed by the chiral tetra(isopropylate)titanium/(S)- or (R)-Binol complex led to the formation of (1?R,2S)-(+)- or (1?R,2R)-(–)-methiin stereomers. 相似文献
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A novel approach for the asymmetric synthesis of (6R)-4-hydroxy-6-substituted-δ-lactones has been achieved using asymmetric reduction of a prochiral ketone in the presence of (S)-(?)-diphenyl-prolinol/borane as a key step. The enantiomeric purity of the products was determined by chiral GC. 相似文献
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从L-α-脯氨酸出发,经过酯化、N-烷基化、与格氏试剂反应合成了6个未见文献报道的(S)-(+)-N-取代吡咯烷甲醇衍生物3a~3f,其结构经IR,1HNMR和元素分析测定确证.并用X射线单晶衍射法测定了化合物(S)-(+)-1-[N-(5-氯-2-噻唑甲基)-2-吡咯烷基]-1,1-二苯基甲醇(3e)的晶体结构.晶体为单斜晶系,空间群为P2(1),a=0.8737(14)nm,b=0.9098(14)nm,c=1.2180(17)nm,α=90.00°,β=92.55(3)°,γ=90.00°,V=0.9671(3)nm3,Z=2,Dc=1.3217g/cm3,F(000)=404,R=0.0584,wR=0.1335. 相似文献
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An easy and efficient one-pot reaction from readily available 2-(N-Cbz) aminocyclobutanone selectively gave, by means of an asymmetric Strecker synthesis in the presence of a chiral benzylic amine, the thermodynamic 1,2-diamino nitriles. Basic hydrolysis, cleavage of the benzylic group and acidic hydrolysis of the resulting trans-1,2-diaminocyclobutanecarbonitrile gave, in a four-step sequence from the ketone, (1S,2S)- or (1R,2R)-1,2-diaminocyclobutanecarboxylic acid, ornithine derivatives. The absolute configuration has been established by X-ray analysis of the corresponding trans-diamino amide. 相似文献
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研究了一种化学不对称合成盐酸(R)-沙丁胺醇的方法. 以自制的手性龙脑基β-二酮铁络合物为催化剂催化起始原料3-乙酰氧基甲基-4-乙酰氧基苯乙烯(1)的不对称环氧化, 得到(R)-3-乙酰氧基甲基-4-乙酰氧基苯基环氧乙烷(2), 这一步的化学收率和光学收率都较高. 然后环氧化合物2与叔丁胺发生开环反应, 再与盐酸成盐即制得盐酸(R)-沙丁胺醇. 合成盐酸(R)-沙丁胺醇只需两步, 总收率为68%. 还考察了反应温度、催化剂种类、催化剂的量等因素对3-乙酰氧基甲基-4-乙酰氧基苯乙烯(1)的不对称环氧化的化学产率和光学收率的影响. 相似文献