双（取代环戊二烯基）二氯化锆的晶体结构分析

用Ｘ－射线晶体结构衍射法测定了双［１－苄基－１－乙基丙基环戊二烯基］二氯化锆［η５－Ｃ５Ｈ４Ｃ（Ｃ２Ｈ５）２ＣＨ２Ｃ６Ｈ５］２ＺｒＣｌ２（Ｉ）及（１，２－二异丁基－１，２－甲基－乙基桥联）双环戊二烯基二氯化锆［η５－Ｃ５Ｈ４Ｃ（ＣＨ３）（Ｃ４Ｈ９－ｉ）Ｃ（ＣＨ３）（Ｃ４Ｈ９－ｉ）Ｃ５Ｈ４－η５］ＺｒＣｌ２（Ⅱ）的结构。二者皆为单斜晶系，（Ｉ）的空间群为Ｐ２／ｎ，ａ＝１２．５８２（３），ｂ＝７．９９２（２），ｃ＝１４．９７９（３）Ａ，β＝１０１．６８（１）°，Ｖ＝１４７４．９（９）Ａ３，Ｍｒ＝６１２．８４，Ｚ＝２，Ｄｘ＝１．３８ｇ／ｃｍ３，μ＝５．６９ｃｍ（－１），Ｆ（０００）＝６４０，Ｒ＝０．０３３，Ｒω＝０．０３６。（Ⅱ）的空间群为Ｃｃ，ａ＝１３．３０９（３），ｂ＝９．５９１（１），ｃ＝１６．４４９（８）Ａ。β＝４．８３（３）°，Ｖ＝２０９．２（２）Ａ３，Ｍｒ＝４５８．６３，Ｚ＝４，Ｄｘ＝１．４５６ｇ／ｃｍ３，μ＝７．７７ｃｍ（－１），Ｆ（０００）＝９５２，Ｒ＝０．０５１，Ｒω＝０．０６１。化合物（Ｉ）以重叠式存在，两个苄基处于反式。晶体（Ⅱ）以交叉式存在，甲基、异丁基以反式构象存在。     

（＋）—1S,2R,5S—8—β—萘基薄荷醇的合成

以Ｒ－（＋）－Ｐｕｌｅｇｏｎｅ为起始原始经１，４－加成、溴代、水解、氧化等９步反应合成了手性辅助试剂（＋）－１Ｓ，２Ｒ，５Ｓ－８－β－萘基薄荷醇及其关向异构体（－）－１Ｒ，２Ｒ，５Ｓ－８－β萘基新薄荷醇，总收率分别为２４．０％和２２．６％。     

6-硫杂-13-氧杂二环[9.3.0]-3,8-二炔十四烷的合成及核磁共振鉴定

以３，４－二（４′－甲磺酰氧－２′－丁炔基）四氢呋喃或６－硫杂－３，８－二炔－１，１１－二羟甲基环十一烷为原料合成了二环化合物６－硫杂－１３－氧杂二环［９．３．０］－３，８－二炔十四烷。通过１ＨＮＭＲ，１３ＣＮＭＲ，ＩＲ及ＭＳ进行了结构鉴定。     

6—硫杂—13—氮杂二环（9.3.0）—3,8—二炔十四烷的合成及核磁共振鉴定

以３，４－二（４′－甲磺酰氧－２′－丁炔基）四氢呋喃或６－硫杂－３，８－二炔－１，１１－二羟甲基环十一烷为原料合成了二环化合物６－硫杂－１３－氧杂二环（９．３．０）－３，８－二炔十四烷，通过＾１ＨＮＭＲ＾１３ＣＮＭＲ，ＩＲ及ＭＳ进行结构鉴定。     

离子选择电极—流动注射分析法动力学测定葡萄糖存在下的果糖

本文将离子电极与流动注射分析相结合，利用３０℃下，在强碱性介质中，果糖和葡萄糖与２，４－二硝基酚钠反应速度明显差异，动力学测定了葡萄糖存在下果糖的含量。自制了２，４－二硝基酚电极作为动力学电位测定用的工作电极。本法测定果糖的范围为０．０２～１．００ｍｏｌ／Ｌ，其ＲＳＤ为４．０％～４．９％，ＲＥ为１．０～５．０％；当Ｃ葡／Ｃ果≤３倍时，葡萄糖的干扰不超过５％；本法也曾成功地用于果葡萄浆测定，其ＲＳＤ     

C70R2（R=OH,CH30的结构和电子光谱

用ＩＮＤＯ方法研究了Ｃ７０Ｒ２（Ｒ＝ＯＨ，ＣＨ３）４种异构体的结构和稳定性，表明１，９－Ｃ７０（ＯＨ）２比７，８－Ｃ７０（ＯＨ）２稳定，两者能量差为３８．５ｋＪ／ｍｏｌ，而７，８－Ｃ７０（ＣＨ３）２比１，９－Ｃ７０（ＣＨ３）２能量低２３．０ｋＪ／ｍｏｌ。以优化构型为基础，对Ｃ７０Ｒ２（Ｒ＝ＯＨ，ＣＨ３）的电子光谱进行了理论预测。     

螺（异苯并呋喃—1（3H）,9‘—（9H）—2’—N,N—二苄胺基—6‘—二乙胺基占吨）—…

合成了螺（异苯并呋喃－１（３Ｈ），９’－（９Ｈ）－２’－Ｎ，Ｎ－二苄胺基－６’－二乙胺基占吨）－酮－３，Ｃ３８Ｈ３４Ｎ２Ｏ５，单斜晶系，空间群Ｃｃ，晶体学参数为ａ＝１６．８２６（４），ｂ＝１０．６４８（４），ｃ＝１７．６１８（７）Ａ，β＝９２．２５（２）°，Ｖ＝３１５４（２），Ａ＾３，Ｚ＝４，Ｍｒ＝５６６．７，Ｄｘ＝１．１９ｇ／ｃｍ＾３，Ｆ（０００）＝１２００。结构由直接法解出，偏离因子Ｒ＝０．０     

杂多阴离子的有机金属化学(Ⅲ)──缺位Keggin阴离子PW_9O_(34)~(9-)的酯基锡杂多配合物的合成及性质

利用酯基锡与缺位Ｋｅｇｇｉｎ结构杂多阴离子ＰＷ９Ｏ９－３４反应，合成了６种新的杂多阴离子有机金属配合物Ｍ９［（Ｒ′ＯＯＣＣＨＲ″ＣＨ２ＳｎＯＨ２）３（ＰＷ９Ｏ３４）２］·ｘＨ２Ｏ（Ｍ＝（ＣＨ３）４Ｎ＋，Ｋ＋；Ｒ′＝ＣＨ３＿，ＣＨ３ＣＨ２＿；Ｒ″＝Ｈ，ＣＨ３＿），通过元素分析、ＩＲ光谱、紫外电子光谱、１ＨＮＭＲ、３１ＰＮＭＰ、１８３ＷＮＭＲ和ＴＧＡ－ＤＳＣ热分析等测试手段对标题配合物进行了表征和性质研究，确定该系列配合物为Ａ－β－ＰＷ９型夹心配合物结构．     

对称三唑Schiff碱与铜的配合物合成及性能

合成了４种新型对称三唑水杨醛Ｓｃｈｉｆ碱的铜配合物［ＣｕＬ１Ｃｌ２］（Ⅰ）和三核配合物［Ｃｕ３（Ｌ２－Ｌ４）２Ｃｌ４］·ｎＨ２Ｏ（Ⅱ～Ⅳ），其中Ｌ１，Ｌ２，Ｌ３和Ｌ４分别为４－氨基－１，２，４－三唑、４－氨基－３，５－二甲基－１，２，４－三唑、４－氨基－３，５－二乙基－１，２，４－三唑和４－氨基－３，５－二羟甲基－１，２，４－三唑的水杨醛Ｓｃｈｉｆｆ碱．经元素分析、电导、红外光谱、热重分析、电子光谱、ＥＳＲ和变温磁化率表征，该类配合物为畸变四方构型．配合物Ⅱ的变温磁化率表明，铜离子间存在弱的反铁磁相互作用，Ｊ＝－１８．９ｃｍ－１，ｇ＝２．０８，Ｆ＝２．７×１０－３．配合物对Ｂ细胞增殖有抑制作用．     

丙酸睾丸素的吸附阴极溶出伏安法研究

在ｐＨ为６．０的Ｂ－Ｒ缓冲溶液中，丙酸睾丸素于电位－１．４Ｖ（ｖｓ．ＳＣＥ）左右处出现一个灵敏的附阴溶出峰。经５ｍｉｎ富集后，阴极溶出峰电流与浓度在１．３８×１０＾－＾８－７．３×１０＾－＾８ｍｏｌ／Ｌ范围内成线笥关系，该方法用于注射液中丙酸睾丸素含量测定，回收率８０％－８６％。检测下限为４．１×１０＾－＾９ｍｏｌ／Ｌ。     

Diastereoselective total synthesis of isocarbacyclin from L-ascorbic acid

Diastereoselective total synthesis of isocarbacyclin, which features a fused bicyclic key intermediate available from l-ascorbic acid, is described. The key intermediate was prepared in multigram quantities by the Pauson-Khand reaction of l-ascorbic acid-based (R)-4,4-diallyl-2,2-dimethyl-5-(trimethylsilyl)ethynyl-1,3-dioxolane (3), discriminating diastereotopic groups and faces of the geminal allyl substituents.     

(R)-2-甲基半胱氨酸盐酸盐的合成方法改进

以L-半胱氨酸甲酯盐酸盐为起始原料,经4步反应合成了(R)-2-甲基半胱氨酸盐酸盐.在关键中间体(2R, 4R)-2-叔丁基-3-甲酰基-4-甲基-1,3-噻唑烷-4-甲酸甲酯(4)的合成中,采用Self-regeneration of stereocenters原理,用六甲基二硅胺钠取代文献方法中的二异丙基胺基锂,4的收率由文献的56%提高至90%.化合物的结构经1H NMR和MS表征.     

甾体植物生长激素合成的研究V: 甾体醛与3-甲基丁烯-2-内酯醛醇反应的立体化学

研究了甾体醛与3-甲基丁烯-2-内酯的醇醛缩合反应的温度与产物的立体化学的关系. 这一反应是合成油菜甾醇内酯植物生长激素边链的关键. 结果发现-78℃是这一醇醛缩合反应的最佳反应温度.     

An alternative synthetic strategy for (3R),(5R)-5-hydroxy-de-O-methyllasiodiplodin and its epimer

A concise total synthesis of (3R),(5R)-5-hydroxy-de-O-methyllasiodiplodin and its epimer have been synthesized from commercially available (R)-propylene oxide and Orsellinic acid as starting materials. The key steps involved in the synthesis are Wittig reaction, epoxide ring opening with 1,3-dithiane intermediate and Yamaguchi macrolactonization.     

Total syntheses of bengamides B and E

Total syntheses of the cytotoxic marine natural products bengamides B and E are described. Both bengamides are prepared via amide coupling of a protected polyhydroxylated lactone intermediate 9 with a suitably substituted aminocaprolactam intermediate. Lactone 9 is prepared in five steps from commercially available alpha-D-glucoheptonic gamma-lactone. The key reactions are a selective deprotection of a 1,2-acetonide in the presence of a 1,3-acetonide and an (E)-selective olefination of an unstable aldehyde using a gem-dichromium reagent. The bengamide B lactam intermediate 10 is prepared in seven steps from commercially available (5R)-5-hydroxy-L-lysine (12). The desired S-configuration at the gamma-OH lactam position is established using the Mitsunobu reaction.     

乌头碱A环中间体的合成

以(R)(-)香芹酮为原料,经环氧异构开环反应、［3+2］环加成应和Kemp消除反应等关键步骤,共9步反应合成了乌头碱A环中间体(1R,2R,4R,6S)-2-苯甲氧基-6-羟基-1-羟甲基-4-丙烯基环己烷腈,总收率25.7%;其结构经¹H NMR, ¹³C NMR, IR, MS(ESI)确证。     

Ab Initio Study on the Mechanism of Cycloaddition Reaction between Silylene Carbene （H_2Si=C：） and Acetone

The mechanism of cycloaddition reaction between singlet silylene carbene and acetone has been investigated with CCSD(T)//MP2/6-31G method. From the potential energy profile, it can be predicted that the reaction has two competitive dominant reaction pathways. One consists of two steps: (1) the two reactants (R1, R2) firstly form a four-membered ring intermediate (INT4) through a barrier-free exothermic reaction of 585.9 kJ/mol; (2) Then intermediate (INT4) isomerizes to CH3-transfer product (P4.1) via a transition state (TS4.1) with energy barrier of 5.3 kJ/mol. The other is as follows: on the basis of intermediate (INT4) created between R1 and R2, intermediate (INT4) further reacts with acetone (R2) to form the intermediate (INT5) through a barrier-free exothermic reaction of 166.3 kJ/mol; Then, intermediate (INT5) isomerizes to a silicic bis-heterocyclic product (P5) via a transition state (TS5), for which the barrier is 54.9 kJ/mol. The presented rule of this reaction: the [2+2] cycloaddition effect between the π orbital of silylene carbene and the π orbital of π-bonded compounds leads to the formation of a four-membered ring intermediate (INT4); The unsaturated property of C atom from carbene in the four-membered ring intermediate (INT4) results in the generation of CH3-transfer product (P4.1) and silicic bis-heterocyclic compound (P5).     

Straightforward synthesis of (S)- and (R)-alpha-trifluoromethyl proline from chiral oxazolidines derived from ethyl trifluoropyruvate

[Structure: see text] A concise synthesis of both enantiomers of alpha-Tfm-proline and (S)-alpha-Tfm-prolinol from ethyl trifluoropyruvate is reported. The key step is a diastereoselective allylation reaction of ethyl trifluoropyruvate and (R)-phenylglycinol-based oxazolidines or imine. The lactone obtained by cyclization of the resulting hydroxy ester proved to be a valuable intermediate for the synthesis of (S)-alpha-Tfm-allylglycine and (S)-alpha-Tfm-norvaline in enantiopure form.     

Diastereoselective synthesis of (2S,5R)-5-hydroxypipecolic acid and 6-substituted derivatives

[reaction: see text] Herein, we report a diastereoselective synthesis of the natural product (2S,5R)-5-hydroxypipecolic acid and 6-substituted derivatives thereof. The key step in the synthetic sequence is a novel highly diastereoselective epoxidation reaction of an enantiomerically pure cyclic enamide intermediate.     

Theoretical studies of mechanism of cycloaddition reaction between germylidene and formaldehyde

Mechanism of the cycloadditional reaction between singlet germylidene (R1) and formaldehyde (R2) has been investigated with MP2/6‐31G* method, including geometry optimization, and vibrational analysis for the involved stationary points on the potential energy surface. The energies of the different conformations are calculated by CCSD(T)//MP2/6‐31G* method. From the potential energy profile, it can be predicted that the dominant reaction pathway of the cycloadditional reaction between singlet germylidene and formaldehyde is reaction (4) , which consists of three steps: the two reactants (R1, R2) first form an intermediate INT1b through a barrier‐free exothermic reaction of 28.1 kJ/mol; this intermediate reacts further with formaldehyde (R2) to give an intermediate INT4, which is also a barrier‐free exothermic reaction of 37.2 kJ/mol; subsequently, the intermediate INT4 isomerizes to a heteropolycyclic germanic compound P4 via a transition state TS4, for which the barrier is 18.6 kJ/mol. The dominant reaction has an excellent selectivity and differs considerably from its competitive reactions in thermodynamic property and reaction rate. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008