(6R,7R)-7-氨基-3-[2-(4-甲基-5-噻唑)乙烯基]-8-氧代-5-硫-1-氮杂双环[4.2.0]辛-2-烯-2-羧酸的合成

以1-磺丁基-3-甲基咪唑硫酸氢盐离子液体(b)为反应介质,7-氨基头孢烷酸(7-ACA,2)为原料,与4-甲基-5-甲酰基噻唑经缩合反应制得(6R,7R)-7-氨基-3-[2-(4-甲基-5-噻唑)乙烯基]-8-氧代-5-硫-1-氮杂双环[4.2.0]辛-2-烯-2-羧酸(7-ATCA,1),其结构经1H NMR,13C NMR和IR表征。考察了离子液体及其用量,原料摩尔比r[n(4-甲基-5-甲酰基噻唑)∶n(2)],反应温度和反应时间对1收率的影响。在最佳反应条件[b为反应介质,b用量为20 m L,r=1.3,于65℃反应5 h]下,1收率可达90%以上。     

A Practical Synthesis of (2S, 3R)-3-Amino-2-methylpentanoic Acid from L-Aspartic Acid

L -Aspartic acid by successive N-tosylation, anhydride formation, and reduction was converted into (3S)-3-(tosylamino)butano-4-lactone ( 4 ). Electrophilic methylation of 4 , subsequent iodo-esterification and nucleophilic methylation, followed by saponification and deprotection, gave (2S, 3R)-3-amino-2-methylpentanoic acid ( 2 ) with an ee of > 99% in seven steps and in an overall yield of 34%.     

7-氨基-3-乙烯基头孢烷酸的合成

以7-苯乙酰氨基-3-氯甲基头孢烷酸对甲氧基苄酯为原料经Wittig反应、水解、酶解三步反应合成重要的药物中间体——7-氨基-3-乙烯基头孢烷酸,总收率71.2%。其结构经1H NMR和IR表征。     

一种制备(1R,3S)-3-氨基-1-环己烷羧酸的新方法

介绍了一种简单的制备(1R,3S)-3-氨基1环己烷羧酸的方法。以环己烷-1,3-二羧酸的顺反混合物为原料。经过关环得顺式的酸酐,然后酯化,在脂肪酶AY-30的作用下进行去对称性水解。得光学活性的环己烷-1,3-二羧酸的单乙酯产物,经过改进的Curtis重排反应后,羧酸基团转变为氨基。然后经过酯水解、去保护基团,得到光学纯的(1R,3S)-3-氨基-1-环己烷羧酸。     

Novel Synthesis of 5-Amino-3-bromo-1-(tert-butyl)-1H-pyrazole-4-carbonitrile: A Versatile Intermediate for the Preparation of 5-Amino-3-aryl-1-(tert-butyl)-1H-pyrazole-4-carboxamides

A simple, novel, and efficient route for the synthesis of 5-amino-3-aryl-1-(tert-butyl)-1H-pyrazole-4-carboxamides 1 has been devised. Preparation of pyrazole bromide 3 from potassium tricyanomethanide can be accomplished in only two steps in good yield and features a selective Sandmeyer reaction on the corresponding diaminopyrazole. This allows for a more versatile synthesis of 5-amino-3-aryl-1-(tert-butyl)-1H-pyrazole-4-carboxamides 1 than was previously possible.     

Chemoenzymatic Synthesis of (R)- and (S)-4-Amino-3-Methylbutanoic Acids

(R)- and (S)-4-Amino-3-methylbutanoic acids were synthesized in high yields via initial enantioselective hydrolysis of dimethyl 3-methylglutarate to methyl (R)-3-methylglutarate with pig liver esterase. The ester group was converted to an amine to give (R)-4-amino-3-methylbutanoic acid; the carboxylic acid was converted to an amine to give (S)-4-amino-3-methylbutanoic acid.     

Asymmetric Synthesis of (-)-(2R,3R,6S)-Irnigaine

Introduction　　Asarelativelynewmemberofnaturalalkaloidswith2 ,6 disubstituted 3 piperidinolskeleton ,irnigaine 1wasisolatedfromthetubersofArisarumVulgare (Araceae)in1995byMelhaouiandBode .1Itsstructureandrelativeconfigurationswereelucidatedby1HNMRstudiesandtheabsoluteconfigurationwasproposedonthebasisofitsopti calrotation .1Soonafterthen ,Meyerandhisco workersreportedthefirstsynthesisof (- ) (2R ,3R ,6S) irni gaineandtheconfigurationconfirmation .Althoughtheirsynthesisroutewasshortan…     

A Convenient Preparation of (R)-7-(3-Benzothienylglycylamido)deacetoxycephalosopranic Acid

An efficient synthesis of (R)-7-(3-benzothienylamido)deacetoxy-cephalosporanic acid (1) is described beginning from (R)-alpha-aminobenzo[b]thiophene-3- acetic acid (2) and 7-amino-3-methyl-3-cephem-4-carboxylic acid (7-ADCA). Good yields were obtained and the procedure is amenable to multikilogram preparations.     

(R)-2-甲基-7-炔-辛酸的合成

以1,5-戊二醇为起始原料,用Evans手性助剂诱导的烷基化反应构造了C-2手性中心,用Ohira-Bestmann试剂制备了末端炔基,通过13步反应,合成了(R)-2-甲基-7-炔-辛酸,总收率为17.1%,e.e.值大于99%.     

An Efficient Synthesis of Tertiaryaminomethylphosphonates,A Versatile Precursor for Synthesis of Glyphosate and α—Aminomethylphosphonates

Reaction of simple dialkyl phosphites with symmetrical 1,3,5-trisubstituted hexahydrotriazines (HHTs) in the presence of benzyl chloride,afforded tertiaryaminomethylphosphonates in excellent yields. Glyphosate,α-aminomethylphosphonates and their derivatives can therefore be synthesized by this procedure conveniently.     

The Synthesis of 3-(R)- and 3-(S)-Hydroxyeicosapentaenoic Acid

Monohydroxylated polyunsaturated fatty acids belonging to the oxylipin class of natural products are present in marine and terrestrial sources as well as in the human body. Due to their biological activities and role in diverse biosynthetic pathways, oxylipins biosynthesized from eicosapentaenoic acid and arachidonic acid have attracted great interest from the scientific community. One example is 3-hydroxyeicosapentaenoic acid where the absolute configuration at C-3 has only been tentatively assigned. In this paper, studies on acetate type aldol reactions that enabled the preparation of 3-(R)-hydroxyeicosapentaenoic acid (3R-HETE, 2) and its enantiomer are presented.     

二苯乙烯氨基酸的合成及其性能研究

以4-碘-L-苯丙氨酸为初始原料，先将羧基和氨基进行保护、后与苯乙烯进行Heck反应，最后在碱性和酸性条件下脱除保护合成二苯乙烯氨基酸，即(E)-2-氨基-3-(4-苯乙烯基苯基)丙酸的盐酸盐（4），产率53.7%，其结构经¹H NMR、 IR和HR-MS(ESI-TOF)表征。光学性质研究结果表明：4的激发波长为312 nm，发射波长为357 nm，斯托克斯位移为45 nm，荧光量子产率为0.09。 4在甲醇溶液中存在光致顺反异构现象，反式→顺式结构转变速率常数为0.046 min^-1。     

A Direct and Versatile Synthesis of 5-(2-Di-n-Propylaminoethyl)-7-methoxyindole

The Pummerer intermediate generated from 10 with TFAA was trapped intermolecularly in the presence of Lewis acid by the indoline 2 at position 5. Sequential treatment of the resulted compound 3 with Ra-Ni, LiAlH₄ and active MnO₂ gave compound 6 in high overall yield.     

A Novel Asymmetric Synthesis of S-(+)-2-Amino-4-Phosphonobutanoic Acid

A novel asymmetric synthetic route to S(+)-2-amino -4-pbosphonobutanoic acid through the cyclic condensation of ethyl-4-diethoxyphosphonyl-2-oxo-butanoate with L-erythro-(+)-1, 2-diphenyl-2-hydrozyethylamine, followed by reduction and hydrolysis is described.     

Synthesis of 1-Amino-6,7-dihydro-7-(hydroxymethyl)-4-nitro-pyrrolo[1,2-f]pyrimidin-3-(5H)-one from 2-Amino-6-methylpyrimidin-3-one

The synthesis of previously unreported 1-amino-6,7-dihydro-7-(hydroxymethyl)-4-nitropyrrolo[1,2-f]pyrimidin-3-(5H)-one starting from 2-amino-6-methylpyrimidin-3-one is described.     

合成8-氨基-3,6-二氧杂辛酸前体的新方法

合成8-氨基-3;6-二氧杂辛酸前体的新方法;二缩三乙二醇;二缩三乙二醇单对甲苯磺酸酯;邻苯二甲酰亚胺基二氧杂辛醇;氨基二氧杂辛酸;合成     

Facile Syntheses of (6S)-6-Fluoroshikimic Acid and (6R)-6-Hydroxyshikimic Acid

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｓｈｉｋｉｍａｔｅｐａｔｈｗａｙｉｓａｎｉｍｐｏｒｔａｎｔｂｉｏｓｙｎ ｔｈｅｔｉｃｓｅｑｕｅｎｃｅｉｎ ｐｌａｎｔｓ ,ｆｕｎｇｉａｎｄｍｉｃｒｏｏｒｇａｎｉｓｍｓｆｏｒｔｈｅｃｏｎｖｅｒｓｉｏｎｏｆｃａｒｂｏｈｙｄｒａｔｅｓｔｏｔｈｅａｒｏｍａｔｉｃａｍｉｎｏａｃｉｄｓ (Ｌ ｐｈｅｎｙｌａｌａｎｉｎｅ ,Ｌ ｔｙｒｏｓｉｎｅａｎｄＬ ｔｒｙｐｔｏｐｈａｎ)ａｎｄｐｒｅｃｕｒｓｏｒｓｔｏｔｈｅｆｏｌａｔｅｃｏｅｎｚｙｍｅｓ ,ａｌｋａｌｏｉｄｓａｎｄｖｉｔａｍｉｎｓ[1] .Ａｓ…     

Efficient One-Pot Synthesis of 3-Amino-7-azaindoles Under Microwave Irradiation

An efficient one-pot synthesis of 3-amino-7-azaindoles was developed, starting from ethyl (3-cyanopyridin-2-yl)carbamate and α -bromoketones by microwave-assisted Thorpe–Ziegler cyclization in the presence of a base. This method features excellent yields, short reaction time (10min), and high functional group compatibility.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]