珊瑚色诺卡氏菌CGMCC 4.1037全细胞催化(RS)-4-氟苯甘氨酸去消旋化为(S)-4-氟苯甘氨酸

珊瑚色诺卡氏菌CGMCC 4.1037全细胞能够催化4-氟苯甘氨酸的(R)-对映体立体反转为(S)-对映体,相反方向的反应不能发生.研究了反应条件对(R)-4-氟苯甘氨酸立体反转的影响.在最优反应条件下,5 mmol/L(R)-4-氟苯甘氨酸和10 mmol/L(RS)-4-氟苯甘氨酸分别立体反转和去消旋化为(S)-4-氟苯甘氨酸,产率为52%和63%,ee为99.5%和99.2%.(RS)-4-氟苯甘氨酸的去消旋化过程是通过珊瑚色诺卡氏菌CGMCC 4.1037全细胞中的两个酶催化反应实现的.(R)-氨基酸氧化酶催化(R)-4-氟苯甘氨酸氧化脱氨形成4-氟苯甲酰甲酸,(S)-氨基酸转移酶催化4-氟苯甲酰甲酸转氨化为(S)-4-氟苯甘氨酸.讨论了4-氟苯甘氨酸两个对映体的代谢途径.     

Study on the Stereoselective Synthesis of Carbapenem Sidechain （2S,4S）-4-Acetylsulphanyl-2- [（S）-l-phenylethylcarbamoyl]- pyrrolidine-l-carboxylic Acid 4-Nitrobenzyl Ester

A stereoselective and economic synthesis of the carbapenem sidechain (2S, 4S)-4-ace-tylsulphanyl-2- [ (S) 1-phenylethyl-carbamoyl] pyrrolidine-l-carboxylic acid 4-nitrobenzyl ester was developed. Due to the effect of spatial hindrance, only the (2S,4S) diastereomer 3 was obtained by coupling 1 and the inexpensive racemic 2 catalyzed by EEDQ.     

3-氧代-4-（2,4,5-三氟苯基）丁腈的合成

以2,4,5-三氟苯乙酸为起始原料,经氯化和酰化反应得2-氰基-3-羟基-4-（2,4,5-三氟苯基）丁-2-烯酸乙酯（2）; 2经水解脱羧合成了3-氧代-4-（2,4,5-三氟苯基）丁腈,总收率61.5%,纯度97.6%,其结构经¹H NMR和MS（ESI）确证。     

Synthesis of Quinolone Analogues： 7-[（2S, 4R）-2-Aminomethyl-4- hydroxypyrrolidin-l-yl] Quinolones

New quinolone derivatives of 7-[(2S, 4R)-2-aminomethyl-4-hydroxypyrrolidin-l-yl] quinolone-3-carboxylic acids were synthesized by condensation of 7-halo substituted quinolone-3-carboxylic acids with (2S, 4R)-2-aminomethyl-4-hydroxypyrrolidine. These compounds were characterized by FAB-MS and IH NMR.     

One-pot Synthesis and Crystal Structure of （1S,2R,3S,4R,5S）-1-Phenyl-2,4-dibenzoyl-3,5-difurylhexanol

(1S,2R,3S,4R,5S)-1-Phenyl-2,4-dibenzoyl-3,5-difurylhexanol 1 was synthesized by one-pot reaction of hypnone and furfurol in alkali H2O/EtOH solution and structurally defined to contain a chair-formed aliphatic carbocycle, on which the bulky substituents occupy the equatorial positions.     

Asymmetric Synthesis of （S）-Dimethyl -4, 4＇-dimethoxy-5, 6, 5＇, 6＇-dimethenedioxybiphenyl-2, 2＇-dicarboxylate

(S)-Dimethyl-4, 4‘-dimethoxy-5, 6, 5‘, 6‘-dimethenedioxy-biphenyl-2, 2‘-dicarbonylate was synthesized in reasonable yield through a series of reactions, including chiral oxazolinemediated asymmetric Ullmann coupling, from methyl 2-bromo-5-methoxy-3, 4-methenedioxybenzoate.     

High-throughput Screening of the Enantioselectivity of Hyperthermophilic Mutant Esterases from Archaeon Aeropyrum pernix K1 for Resolution of （ R, S ） -2-Octanol Acetate

To identify the desired hyperthermophilic variants within a mutant esterase library for the resolution of (R,S)-2-octanol acetate, a simple, reliable, and versatile method was developed in this study. We built a screening strategy including two steps, first we selected agar plate with substrate to screen the enzymatic activity; secondly we used a pH indicator to screen the enantioselectivity. This method could rapidly detect favorable mutants with high activity and enantioselectivity. A total of 96.2% of tedious screening work can be precluded using this screening strategy. It is an effective screening for alkyl ester and can be applied to relative screening researches. The four improved mutants were screened from the mutant esterase library. Their enantioselectivities, activities, and structures were investigated at different temperatures.     

(4S)-4-羧基杂氮硅三环的合成

利用L-N,N-双(β-羟乙基)丝氨酸及L-N,N-双(β-羟乙基)苏氨酸与三乙氧基硅烷或氯烷基三乙氧基硅烷反应合成了具有手性的(4S)-4-羧基杂氮硅三环(1～5),并运用IR、~1HNMR、EI-MS等手段表征了结构。证据显示存在着贯穿笼状结构的N→Si配键。     

A New Chiral Synthesis of Naturally Occurring (-)-(S)-4-Hydroxy-2-pyrrolidinone

4-Hydroxy-2-pyrrolidinoneIisanattractivesimplemolecule.First,ithasservedasakeyintermediateinthesynthesis'ofoxiracetam,adrugusefulforimprovinglearningandmemory.Second,IcanbeeasilytransformedintoantiepilepticandhypotensivedrugGABOB',andhypolipidemicagentcarnitine'.Third,(-)-4-hydroxy-2-pyrro-lidinoneIhasbeenisolated'fromthetoadstollAmanitamuscaria.Itsabsoluteconfigurationhasbeenerroneouslyassigned'as(R).ThefirstchiralsynthesisofthiscompoundhasbeenreportedbyPifferi#.However,notuntil1984didi…     

Synthesis of (4S)-4-Carboxyl-1-oxoperoxovanatranes

Anumberofvanadiumhaloperoxidasehavebeenisolatedfrommarinealgaeandlichen'andarethoughttobeinvolvedintheproductionofalargenumberofhalogenatedorganicsinvivo2.Theactivesiteisshowntoconsistofanoxovanadium(V)withN/Odonors3-5.Somevanatranecompounds(2.8.9-trioxa-5-aza-l-vanabicycl[3.3.3]un-decanes)havebeencharacterizedasfunctionalmodelfromthevanadiumhaloperoxidasesenZymes'.Infact,manyclassesofmetalatranecompoundshavebeensynthesizedandstudiedbecauseoftheirspecificstructureandbiologicalactivity'.Recen…     

有机相中利用脂肪酶催化的醇解反应拆分炔丙醇酮乙酸酯

 研究了有机相中脂肪酶催化的炔丙醇酮乙酸酯的立体选择性醇解反应, 考察了碱的种类、酰基受体和溶剂等对反应的影响. 结果表明, 以四氢呋喃为溶剂, CH3OH 为酰基受体, Lipase PLG 脂肪酶为催化剂, Na2CO3 为碱性添加剂, 高底物浓度下 40 oC 反应 96 h 后, 底物转化率和产物 ee 值分别达到 49.5% 和 99.5%. 碱的添加极大地提高了反应速度.     

(4R,5S)-5-羟基-4-甲基-3-己酮的合成

农业害虫药材甲Stegobium panicem Linnae在我国各省区都有分布,主要危害谷类、食品、药材、图书、档案等.我国一般每年可以发2～3代,温度较高的地区可发生4代[1] .     

Synthesis of (4R)-Methylnonan-1-ol and (4R,8RS)-Dimethyldecanal from (S)-(+)-3,7-Dimethyl-1,6-octadiene

Optically active (4R,8RS)-dimethyldecanal, an analog of the aggregation pheromone of the flour beetles Tribolium confusum and T. Castaneum, and (4R)-methylnonan-1-ol, the sex pheromone of the yellow mealworm Tenebrio molitor L., are synthesized using ozonolytic transformation of (6R,10)-dimethyl-9-undecen-2-one to (6R)-methyl-9-hydroxynonan-2-one in the key step. The starting compound is available as enantiomerically enriched (ee ~50%) (S)-(+)-3,7-dimethyl-1,6-octadiene.     

Synthesis of （S）-2-（3-Arylacrylamido）-3-{4-[2-（5-methyl-2-phenyloxazol-4-yl）ethoxy]phenyl}propanoic Acids

The synthesis of （S）-2-（3-arylacrylamido）-3-{4-[2-（5-methyl-2-phenyloxazol-4-yl）etho- xy]phenyl}propanoic acids is described. Their structures were confirmed by ^1H-NMR.     

(3S,4S)-4-氨基-3-羟基-6-甲基庚酸的合成

价廉易得的L-亮氨酸先以苄基同时保护氨基及羧基得(S)-2-(二苄胺基)-4-甲基戊酸苄酯,进而在碱性条件下与乙腈发生亲核取代反应得(S)-4-(二苄胺基)-6-甲基-3-氧代庚腈,再经硼氢化钠选择性还原羰基得(3S,4S)-4-(二苄胺基)-3-羟基-6-甲基庚腈,用双氧水氧化得(3S,4S)-4-(二苄胺基)-3-羟基-6-甲基庚酸,最后在Pd(OH)2/C-H2作用下脱掉苄基得到(3S,4S)-4-氨基-3-羟基-6-甲基庚酸,即(3S,4S)-statine。整个合成路线总产率为33.6%。     

(S)-(4-溴-2-甲苯)(3-甲基吗啉)甲酮的合成

以(S)-2-氨基丙醇和氯乙酰氯为起始原料,经酰化和环合反应制得(S)-5-甲基吗啉-3-酮（4）; 4经还原制得(S)-3-甲基吗啉(5); 5与4-溴-2-甲基苯甲酸酰化缩合合成了(S)-(4-溴2-甲基苯基)(3-甲基吗啉)-甲酮,总收率57%,其结构经¹H NMR 和 ¹³C NMR确证。     

(2S,4S)-苯甲基-2-(6-氟-1H-吲哚-3-羰基)-4-羟基-吡咯烷-1-羧酸酯的合成

以4-羟基-L-脯氨酸为原料,经Cbz保护、偶联、Mitsunobu反应和水解合成了抗肿瘤新药Birinapant的重要中间体--(2S,4S)-苯甲基-2-(6-氟-1H-吲哚-3-羰基)-4-羟基吡咯烷-1-羧酸酯,总收率83%,其结构经¹H NMR和ESI-MS确证。