(2S, 3R, 4R)-4, 5-O-异亚丙基-2, 3-环亚硫酰-2, 3, 4, 5-四 羟基戊酸乙酯 中硫原子手性的研究

我们在合成鞘氨醇3时,成功地分离到一对环亚硫酸酯1由于硫原子手性形成的非对映异构体,通过氢核磁共振谱分析和分子力学计算,确定了它们手性硫原子的绝对构型.     

[Hg(C_5H_4S_5)I_2]_2的合成与晶体结构(C_5H_4S_5=4,5-亚乙基二硫杂-1,3-二硫杂-2-硫酮)

用 HgI2 和 4,5-亚乙基二硫杂-1,3-二硫杂-2-硫酮 (C5H4S5)反应,合成一种二核汞配合物[Hg(C5H4S5)I2]2 1。X 射线衍射结果表明,晶体属于单斜晶系,C2/c 空间群,晶胞参数 a =21.6847(1),b = 8.5125(4),c = 15.6699(8),a=112.7850(1)°,V=2666.8(2) ?3。Mr = 1357.54,Z = 4,Dx = 3.381 g/cm3,ì = 16.913 cm–1,F(000) = 2400,R=0.0639,wR=0.1711,S=1.052。配合物 1 具有二聚体结构,2 个汞原子通过 2 个碘原子桥联,形成 1 个 Hg2I2菱形平面,汞原子周围的配位是四面体结构,通过分子间的硫…硫作用和碘…硫作用,形成准二维超分子网络。 S S S H g I I S S S S I I H g S     

5-取代苯胺基-6-苯基-1, 2, 4-三嗪-3-硫酮的合成

苯甲酰基-N-取代苯基硫代甲酰胺和氨基硫脲反应, 首先在酸性介质中形成缩氨基硫脲, 然后在碱性介质(pH=8~9)中环化, 生成5-取代苯胺基-6-苯基-1, 2, 4-三嗪-3-硫酮。本文合成10个新的该类杂环化合物。     

微波炉加热法合成3-芳基-1, 2, 4-三唑啉-5-硫酮

本文报道了微波炉加热法合成3-芳基-1, 2, 4-三唑啉-5-硫酮,研究了反应时间, 溶液用量, 微波功率及芳基对反应产物收率的影响。     

新拆分试剂R(-)四氢噻唑-2-硫酮-4-羧酸对R,S-α-苯乙胺拆分的研究

Ｒ（－）四氢噻唑－２－硫酮－４－羧酸［简称Ｒ（－）ＴＴＣＡ］可作为检查尿样中ＣＳ２含量的标准试剂，我们对其结构［１］及性质进行了研究，发现它有很好的手性识别功能，可作为新的拆分试剂对Ｒ，Ｓ－α－苯乙胺进行拆分．光学活性的α－苯乙胺已被广泛地用来代替光...     

6,7-亚甲二氧基-3-硫杂-1(2H,4H)吖啶酮的氨类衍生物及五元杂环并硫杂吖啶的合成

吖啶类化合物在抗疟和抗癌的药用研究中具有显著的作用^[1,2]，尤其在临床抗疟中广泛地应用了该类药物。为了深入进行吖啶化学的研究,我们将杂原子引入到吖啶环系中,完成了氧杂吖啶的合成^[3]、硫杂吖啶酮及其并六元杂环的研究工作^[4]。本文进一步报告6,7-亚甲二氧基-3-硫杂-(2H,4H)吖啶酮的氨类衍生物及其并五元杂环化合物的合成。     

3-取代胺甲基-5-连三唑基-1, 3, 4-恶二唑-2-硫酮的合成

2-苯基-1,2,3-三唑-4-甲酰肼(1)在CS~2/KOH作用下环化得到5-(2-苯基-1,2,3-连三唑-4-基)-1,3,4-恶二唑-2-硫酮(2),2经Mannich反应合成得到标题化合物3-(取代胺甲基-5-(2-苯基-1,2,3-连三唑-4-基)-1,3,4-恶二唑-2-硫酮(3)。     

R(-)四氢噻唑-2-硫酮-4-羧酸对D,L-氨基酸酯拆分的研究

以新手性拆分试剂R(-)四氢噻唑-2-硫酮-4-羧酸[简称R(-)TTCA]对D,L-氨基酸酯进行手性拆分,分别得到(R)TTCA氨基酸酯盐1a_1f([α]_D²⁰＝-30.40°～-42.70°)及光学活性氨基酸酯2a-2f,其光学纯度为35.4%～75.8%.由1a_1f在碱存在下分解出2a-2f的对映体3a-3f,光学纯度为39.50%～69.10%.用半经验的量子化学PM3方法研究了氨基的碱性、中间产物铵盐生成热和稳定性.     

双高烯丙基硫醚和β,γ-及γ,δ-不饱和缩硫酮的区域专一性碳钯化反应

本工作试图把碳钯化反应发展到双主主烯丙基体系,以考察通过杂原子导向的远端区域专一性的反应以及缩硫酮官能团对硫钯化反应的导向作用.     

(R)-2-硫代四氢噻唑-4-羧酸及其酯的合成

L-半胱氨酸盐酸盐与二硫化碳, 氢氧化钠在硝酸铅存在下进行成环反应得到(R)-四氢噻唑-2-硫酮-4-羧酸产率76% , 后者与 醇在硫酸铁水合物催化下反应得到(R)-四氢噻唑-2-硫酮-4-羧酸酯, 产率40～82% .     

Stereoselective synthesis of (2R,3S,4S,5R)-trans-3,4-dihydroxy-5-(4-fluorophenoxymethyl)-2-(1-N-hydroxyureidyl-3-butyn-4-yl)tetrahydrofuran and (2R,3S,4S,5R)-trans-5-ethynyl-2-(4-fluorophenoxymethyl)-3,4-O-isopropylidene tetrahydrofuran from mannose diacetonide

Stereoselective synthesis of pharmaceutically interesting chiral tetrahydrofurans starting from mannose diacetonide is reported. A 1,4-diol system derived from mannose diacetonide, through a Mitsunobu reaction was stereospecifically cyclized to give chiral tetrahydrofurans. Both the C-1 and C-4 centers of d-mannose are successfully exploited to install the requisite side chains.     

Studies on the transformation of nitrosugars into iminosugars III: synthesis of (2R,3R,4R,5R,6R)-2-(hydroxymethyl)azepane-3,4,5,6-tetraol and (2R,3R,4R,5R,6S)-2-(hydroxymethyl)azepane-3,4,5,6-tetraol

A divergent synthesis of the two novel polyhydroxylated azepanes (2R,3R,4R,5R,6R)-2-(hydroxymethyl)azepane-3,4,5,6-tetraol and (2R,3R,4R,5R,6S)-2-(hydroxymethyl)azepane-3,4,5,6-tetraol from d-mannose is described. The method involves a Henry reaction between dimethyl-tert-butylsilyl 2,3-O-isopropylidene-α-d-lyxo-pentodialdo-1,4-furanoside and 2-nitroethanol followed by a reductive ring closure of the resulting epimeric nitro aldols. Glycosidase inhibition tests showed that (2R,3R,4R,5R,6S)-2-(hydroxymethyl)azepane-3,4,5,6-tetraol exhibits a weak but selective inhibition against α-l-fucosides.     

Synthesis of 2S-Hydroxymethyl-3R, 4R-dihydroxypyrrolidine

Manyp0lyhydroxylatedalkaIoidsexhibitglyc0sidaseinhibit0ryactivitiesl.PoIyhyroxylatedpyrroIidineisatypeofimportantalkaloidalglycosidaseinhibit0rs2.Forexample,2R-hydroxymethyl-3R,4R-dihydroxypyrr0lidine(l,4~dideoxy-1,4imin0-D-arabinitoI),anaturallyoccurringp0lyhydroxylatedpyrrolidine',isapotentinhibitorofa-glucosidase'.Promptedbyinterestsintheremarkablephysi0logicaleffects,s0mepolyhydroxylatedpyrrolidineandtheirderivativeshavebeensynthesized".Inthispaper,wedescribethesynthesis0f2Shydroxymeth…     

Synthesis of enantiomerically pure (3R,4R,5R)-4-hydroxy isoleucine lactone

A short four-step synthesis of (3R,4R,5R)-4-hydroxyisoleucine lactone with total control of stereochemistry is reported, the key intermediate being the didehydroamino acid derivative arising from an aldol dehydration reaction between a glycine anion equivalent and butan-2,3-dione.     

Modified synthesis of methyl (1R,2R,3E,5R)-3-(hydroxyimino)-5-methyl-2-(1-methylethyl)-cyclohexanecarboxylate from (R)-4-menthen-3-one

A modified stereospecific synthesis of potentially biologically and pharmacologically active methyl (1R,2R,3E,5R)-3-(hydroxyimino)-5-methyl-2-(1-methylethyl)cyclohexanecarboxylate from (R)-4-menthen-3-one was developed using sequential 1,4-conjugate addition of Norman reagent catalyzed by CuI?CBF₃?Et₂O?CCuCl₂ and ozonolysis?Creduction of the intermediate (R,R,R)-vinylmenthone by hydroxylamine hydrochloridein MeOH.