A new Sequiterpenoid from Eupatorium adenophorum Spreng

A new sequiterpenoid compound 8aα-hydroxy-1-isopropyl-4,7-dimethyl-1,2,3,4,6,8a-hexahydro-naphthalene-2,6-dione(1),together with seven known compounds anti-HH-dimer-coumarin(2),(-)-5-exo-hydroxy-bomeol(3),O-hydroxyl cinnamic acid(4),9β-hydroxy-ageraphorone(5),10Hα-9-oxo-ageraphorone(6),10Hβ-9-oxo-ageraphorone(7)and 9-oxo-10,11-dehydroageraphorone 8,was isolated from the leaves of Eupatorium adenopho-rum Spreng.The structures were elucidated by IR,~1H and ~(13)C NMR,EIMS,HMBC and single-crystal X-ray spec-tral data.     

Molecular structures of regioisomeric 7‐arylidene hexahydroindazoles from 1H NMR spectra

The structural characterization of two regioisomeric products of the interaction of 2,6‐bis‐(4‐methoxybenzylidene)‐3R‐methylcyclohexanone with methyl hydrazine was achieved using ¹H NMR spectral data, including chemical shifts, coupling constants and results of COSY and nuclear overhauser effect (NOE) experiments. Configurations of the new chiral centers in the (3S,3aR,6R,7E)‐7‐(4‐methoxybenzylidene)‐3,4,5,7‐hexahydro‐3‐(4‐methoxyphenyl)‐2,6‐dimethyl‐ and 2,4‐dimethyl‐2H‐indazoles were assigned on the basis of experimental data combined with molecular modeling by the density functional theory (DFT) method. The distinction in the helical twisting power of studied compounds under addition to a nematic liquid crystal is discussed on the basis of peculiarities of the molecular structures. Copyright © 2009 John Wiley & Sons, Ltd.     

1H, 13C and 15N NMR investigation of a new,condensed hexahydro‐1,3,5‐triazine

Treatment of 2‐acetyl‐2‐methylcyclopentanone with hydrazine hydrate yielded a new condensed hexahydro‐1,3,5‐triazine (3b), which is the first example of the ketimine‐type trimers. A complete ¹H, ¹³C and ¹⁵N NMR assignment of the compound was achieved. Copyright © 2003 John Wiley & Sons, Ltd.     

First report of anti-inflammatory chromenyl derivatives from the spineless cuttlefish Sepiella inermis

Abstract

The spineless cuttlefish Sepiella inermis encompasses a major share in the marine fisheries sector, and represents as a culinary delicacy in many cultures. Bioactivity-guided fractionation of methanol:ethyl acetate (MeOH:EtOAc, 1:1) extract of the edible parts of the species ensued in identification of two hexahydro chromenyl analogues namely, methyl 7-ethyl-hexahydro-8a-methyl-2H-chromene-4-carboxylate (1) and methyl 1-acetoxy-hexahydro-3-methyl-3-propyl-1H-isochromene-4-carboxylate (2). The isolated metabolites were checked for their radical scavenging and anti-inflammatory potentials by selective in vitro models. The isochromenyl derivative exhibited potential 2,2-diphenyl-1-picryl-hydrazil and 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (IC₅₀?<?0.45?mg mL^?1) radical-scavenging capacities along with pro-inflammatory cyclooxygenase-2 (COX-2) (IC₅₀ 0.75?mg mL^?1) and 5-lipoxygenase (5-LOX) (IC₅₀ 0.77?mg mL^?1) inhibitory activities. The titled compounds displayed the selectivity indices (IC₅₀ anti-COX-1/IC₅₀ anti-COX-2) greater than 1.25, in comparison with synthetic anti-inflammatory drug ibuprofen (0.44), which attributed to their greater selectivity towards inducible pro-inflammatory enzyme COX-2.     

An Efficient Synthesis of Spiro‐oxindole Derivatives by Three‐Component Reactions in Water

An efficient synthesis of (3S)‐1,1′,2,2′,3′,4′,6′,7′‐octahydro‐9′‐nitro‐2,6′‐dioxospiro[3H‐indole‐3,8′‐[8H]pyrido[1,2‐a]pyrimidine]‐7′‐carbonitrile is achieved via a three‐component reaction of isatin, ethyl cyanoacetate, and 1,2,3,4,5,6‐hexahydro‐2‐(nitromethylidene)pyrimidine. The present method does not involve any hazardous organic solvents or catalysts. Also the synthesis of ethyl 6′‐amino‐1,1′,2,2′,3′,4′‐hexahydro‐9′‐nitro‐2‐oxospiro[3H‐indole‐3,8′‐[8H]pyrido[1,2‐a]pyrimidine]‐7′‐carboxylates in high yields, at reflux, using a catalytic amount of piperidine, is described. The structures were confirmed spectroscopically (IR, ¹H‐ and ¹³C‐NMR, and EI‐MS data) and by elemental analyses. A plausible mechanism for this reaction is proposed (Scheme 2).     

One‐Pot Synthesis of 5,7,8,9,9a,10‐Hexahydro‐8‐thioxotetrahydropyrido[2,3‐d : 6,5‐d′]dipyrimidine‐2,4,6(1H,3H,5aH)‐triones via a Four‐Component Coupling Reaction of Aldehydes,Amines, Barbituric Acids,and Thiouracil

An efficient one‐pot approach to the synthesis of 5,7,8,9,9a,10‐hexahydro‐8‐thioxopyrido[2,3‐d : 6,5‐d′]dipyrimidine‐2,4,6(1H,3H,5aH)‐triones 5 via a four‐component reaction of an aldehyde 1 , an amine 2 , a barbituric acid 3 , and thiouracil ( 4 ) is reported for the first time. This new multicomponent reaction is accomplished in refluxing EtOH in the presence of tungstophosphoric acid (H₃PW₁₂O₄₀) as a catalyst. A variety of hexahydropyrido[2,3‐d : 6,5‐d′]dipyrimidinetrione derivatives were successfully synthesized in excellent yields with this protocol (Table 2).     

Microwave Assisted Synthesis of Fluorinated Hexahydro 1,3,5‐Triazine Derivatives in Aqueous Medium and One Pot Synthesis of 1,2,4‐Triazolo(4,3‐a)1,3,5‐triazines

Abstract

A multi‐component condensation of substituted phenylthiourea/urea, aqueous formaldehyde and substituted aromatic/heterocyclic amines lead to 2‐thioxohexahydro‐1,3,5‐triazines (4) in aqueous medium under microwave irradiation in 30–60 sec in quantitative yield with reasonable purity. Further, triazolo[4,3‐a]triazines were also prepared by a one‐pot reaction of ‘in situ’ synthesized triazinyl hydrazine (7) with CS₂ (9).     

HPLC法拆分(-)-2(S)-苄基-4-酮-4-(顺式-全氢化异吲哚-2-基)丁酸钙对映体

目的：建立刺激胰岛素分泌的新型降糖药物(-)-2 (S)-苄基-4-酮-4-(顺式-全氢化异吲哚-2-基)丁酸钙对映体的HPLC拆分方法。方法：采用Sumichiral OA-3300手性柱(250 × 4.6 mm I.D., 5 μm), 柱温35℃,以0.05 mol·L-1醋酸铵的甲醇溶液为流动相,检测波长为210 nm。结果：本品两对映体在22分钟内实现良好分离,分离度达3以上,S－异构体分别在0.028 ~ 5.6 μg mL-1和0.03 ~ 6.0 μg mL-1范围内线性关系良好,回归方程分别为：Y=1.32×103x-2.54 (r=0.9997)和Y=1.15×103x-1.78 (r=0.9998),最低检测限分别为0.15 ng和0.10 ng,方法精密度RSD低于1.0% (n=5)。结论：建立的对映体分离方法可用于本品光学异构体的质量控制。     

Stereoselective Synthesis of (2S, 8S)‐2‐Benzyl Hexahydro‐pyrrodizin‐3‐one Starting from (L)‐Proline Based on Stereoselective Benzylation

Abstract

A pyrrolizidine alkaloid, (2S, 8S)‐2‐benzyl hexahydro‐pyrrodizin‐3‐one, was synthesized from (L)‐proline using diastereoselective benzylation as the key step. The absolute configuration of the target compound was confirmed through 2D H‐H COSY and H‐H NOESY spectra.     

Molybdenum‐ and Tungsten‐Based Coordination Polymers as Catalysts for an Efficient and Rapid Synthesis of Hexahydro‐5‐oxoquinoline‐3‐carboxylates and 1,4‐Dihydropyridine‐3,5‐dicarboxylates

Hexahydro‐5‐oxoquinoline‐3‐carboxylates and 1,4‐dihydropyridine‐3,5‐dicarboxylates were synthesized efficiently and rapidly (2 min) in the presence of molybdenum‐ and tungsten‐based coordination polymers [M(Bu₃Sn)₂O₄)]_n (M=Mo or W) as catalysts (Schemes 1 and 2; Tables 2 and 3). The products were formed at room temperature in excellent yields (90–98%). The catalysts worked under heterogeneous conditions and were recyclable. The earlier reports for the application of these polymers to conduct organic synthesis are limited. The present method explores a new and useful application of these catalysts.