Controlled/"Living"?Radical Polymerization of (-)-Menthyl Methacrylate

The atom transfer radical polymerization(ATRP) of (-)-menthyl methacrylate((-)-MnMA) mediated by CuCl/bipyridine and ethyl 2-bromopropionate or 1-phenylethyl bromide in THF system has been studied. The dependence of the specific rotation on molecular weight and the CD of Poly((-)-MnMA) thus obtained was investigated.

Asymmetric Polymerization of Menthyl Methacrylate by Anionic Catalysts

In this paper, (-)menthyl methacrylate((-)MnMA) was polymerized at 78C in toluene with three types of anionic catalysts, which were complexes of fluorenyllithium with (-)sparteine - ((-)-Sp) , (S, S)-(+)-2, 3-dimethoxy-1, 4-bis(dimethylamino)butane((+)DDB) and N,N,N,N-tetra- methylethylenediamine(TMEDA), and the chiral optical property of the obtained polymer was studied. The circular dichroism (CD) spectrum of the polymer showed negative Cotton effect.

Reverse Atom Transfer Radical Polymerization of (-)-Menthyl Methacrylate

The reverse atom transfer radical polymerization(RATRP) of (-)-menthyl methacrylate ((-)-MnMA) with AIBN(AIBN/CuCl2/bipyridine(bipy) or (-)sparteine((-)Sp) =1/2/4) initiating system in THF has been studied. The dependence of the specific rotation on molecular weight was investigated.

Pyrolysis-GC/MS of Menthyl Esters of N-Benzoxycarbonyl Amino Acid

With the aid of a Pyrolysis-GC/TOF MS technique, the pyrolysis behaviour of two menthyl esters of N-benzoxycarbonyl amino acid was investigated. A clear pattern emerges involving the cleavage of the bond linking the menthyl ring to the carboxy group, followed by further degradation of the fragments. The major pyroproducts were p-menth-l-ene pyrolysed at a higher temperature or p-menth-2-ene pyrolysed at a lower temperature, and various derivatives of cyclohexene pyrolyzed from the menthyl ring. In addition, some of the products were also iden- tified as derivatives of benzene from the pyrolysis of benzyloxyl moiety.

ASYMMETRIC SYNTHESIS Ⅻ:HIGHLY ENANTIOSELECTIVE SYNTHESIS OF α-AMINO ACIDS BY ALKYLATION OF THE KETIMINE FROM 2-HYDROXY-PINAN-3-ONE AND MENTHYL GLYCIN-ATE A DOUBLE ASYMMETRIC INDUCTION SYSTEM

A series of α-amino acids are obtained in 72-96% optical yields by alkylation of the ketimine derived from(+)-2-hydroxy-pinan-3-one and(-)-menthyl glycinate fol- lowed by hydrolysis of the alkylated intermediates with mineral acid.The double asymmetric induction are explained by the transition model of lithium enolate.

Determination of Enantiomeric Composition of Substituted Tetrahydroisoquinolines Based on Derivatization with Menthyl Chloroformate

A method for the analysis of the optical purity of a series of chiral substituted tetrahydroisoquinolines (THIQs) was developed. The method is based on pre-column derivatization of the analytes with the derivatization reagent (–)-(1R)-menthyl chloroformate. The derivatization reaction selectively gives diastereomeric carbamates that are resolvable on an achiral non-polar GC column. The developed technique covers variously substituted THIQs, which differ significantly in volatility, steric and electronic properties. In all cases, the resolution factors (R) exceeded the value of 1.5. The method represents a robust way of analysis of mixtures of THIQs, which are often present in various matrixes such as body fluids, tissues and reaction mixtures.

Graft of Chiral Amino Alcohol onto Poly（menthyl vinyl ketone） and the Grafted Polymer＇s Inducement to the Asymmetric Addition of Phenylacetylene to Aromatic Ketone

A new kind of optically active polymer bearing chiral amino alcohol was prepared by means of graft. The resulting grafted polymer was obtained as follows. First, the carbonyl of optically active helical poly（menthyl vinyl ketone）（poly-MVK） was reduced to hydroxyl group with lithium aluminum hydride as a reductant to yield poly（1-menthyl-2-propen-1-ol）（poly-MPO）. Second, the hydroxyl group of poly-MPO reacted with epichlorohydrin to yield methyloxirane-loading poly-MPO[（poly-MPO）-MO]. Third, the（poly-MPO）-MO reacted with amine to pro- duce optically active polymer bearing chiral amino alcohol[（poly-MPO）-APO]. The （poly-MPO）-APO was applied to the asymmetric addition of phenylacetylene to aromatic ketone. Good enantioselectivities were achieved and the catalyst could be recovered and reused 5 times with unchanged enantioselectivity and slightly decreased activity.

Competitive coupling of amide anion over menthyl propionate anion with aryl radical

A competitive coupling of amide anion over menthyl propionate anion with aryl radical in photo-S_(RN) 1 mechanism was encountered. The rcaction afforded N-aryl propionic amide in excel- lent yield. In contrast, the expected nucleophilic photo-S_(RN) 1 substitution originating from the carb- anion was observed in the case of t-butyl propionate. According to the proposed mechanisms and MO correlation diagrams of the coupling step of nucleophiles with aryl radical, the interesting con- trast is reasonably attributed to the variation in energy gap between π~*c-o and π~*Ar of (ArNu)- Usually, the odd electron of (ArNu)- is weightly populated at π~*c-o, however, the diminished priv- ilege of π~*c-o in menthyl propionate promotes a dominant population of the odd electron at π~*Ar, which leads to the fragmentation of (ArNu)- into the starting carbanion and aryl radical.

Asymmetric syntheses of α-amino acids via double chiral induction in alkylation of the ketimine derived from 2-hydroxypinan-3-one and menthyl glycinate

Asymmetric syntheses of (S)-α-amino acids in 28--98% optical yields via double chiral induction in alkylations of ketimine 1 derived from (+)-2-hydroxypinan-3-one and (-)-men- thyl glycinate which is a chiral match pair have been studied. The factors controlling the diastereoselec- tivities in alkylation reactions of the ketimine, the properties of alkylating agents and various alkylation conditions are examined.

L-乳酸薄荷酯的合成及其在个人护理用品中的应用研究

以发酵乳酸和天然薄荷醇为主要原料用直接酯化法合成了乳酸薄荷酯,讨论了合成过程中带水剂的选择、投料配比、反应温度和反应时间对反应转化率的影响。实验结果表明,以四氯化碳为带水剂,m(乳酸)∶m(薄荷醇)=1.2∶1,110℃反应3 h,薄荷醇对乳酸薄荷酯反应转化率可达75.5%。产品经减压蒸馏、重结晶处理后质量分数达99.6%。将其作为清凉剂应用于沐浴露、护肤乳液、爽身粉等个人护理化学品的配方中,并与传统清凉剂薄荷脑进行了性能对比研究。结果表明此产品应用于个人护理用品中,在人皮肤上的清凉作用和感觉方面与薄荷脑相比较更为温和而持久。

GC-MS法同时测定伤湿止痛膏中樟脑 薄荷脑 冰片 水杨酸甲酯的含量

目的建立GC-MS法同时测定伤湿止痛膏中樟脑、薄荷脑、冰片、水杨酸甲酯的分析方法。方法采用GCMS法进行测定。色谱条件:Agilent HP-5MS毛细管柱(0.25mm×30m,0.25μm),进样口温度:200℃,柱温:82℃,保持30min,载气为高纯氦气,流速:1ml·min-1,进样量:1μl,分流比25∶1,以萘为内标。质谱条件:EI离子源,轰击电压:70eV,离子源温度:230℃,四极杆温度:150℃,辅助接口温度:200℃,采用全扫描模式获得混合对照品溶液的总离子流色谱图,确定各目标化合物的保留时间和特征离子,再进行选择离子检测(SIM)定量,选择m/z 95、71、95、128、120分别为樟脑、薄荷脑、冰片(龙脑及异龙脑)、萘、水杨酸甲酯的检测离子。通过内标法同时对伤湿止痛膏中4个主要有效成分进行定性及定量分析。结果伤湿止痛膏中樟脑、薄荷脑、冰片、水杨酸甲酯在16min内全部检出,且分离效果较好;在各自的浓度范围内均有良好的线性关系(r均为0.999以上);平均回收率在98.2%～100.0%范围内。结论经过方法学验证,本文GC-MS法可对伤湿止痛膏的质量进行有效控制。

AOT反胶束体系中脂肪酶催化合成乙酸薄荷酯

在AOT正/己烷构建的反胶束体系中,以CRL脂肪酶为催化剂,乙酸和薄荷醇为原料,合成了乙酸薄荷酯,考察了反应温度、底物浓度、薄荷醇与乙酸摩尔比和反应时间等因素对其转化率的影响,并进行了折光率和红外光谱分析。结果表明,当薄荷醇与乙酸摩尔比为1∶2,乙酸浓度为0.2 mol/L,反应温度为40℃,缓冲溶液的pH值为7.0,含水量W0=10和反应时间为48h时,乙酸薄荷酯的酯合成转化率达到85.3%。

麻黄碱对映异构体的柱前手性衍生化-反相高效液相色谱法拆分

建立了一种用柱前手性衍生化 -反相高效液相色谱法分析麻黄碱对映异构体的方法;以( -)_氯甲酸薄荷醇酯作为手性衍生化试剂 ,( -)_麻黄碱与( +)_麻黄碱衍生化后生成一对非对映异构体,选用HypersilC18柱 ,以乙腈 -水 -乙酸 -三乙胺 (体积比29∶20∶0.2∶0.01)为流动相 ,在254nm下检测,色谱流分经电喷雾离子阱多级质谱分析验证;非对映异构体色谱峰的保留时间分别为17.1min和18.3min ,分离度为1.6;该法操作简单、快速、重现性好 ,可用于药品质量控制和对映体选择性药物动力学研究。

薄荷醇糖苷的合成、纯化与表征

为了开发热稳定的、致凉型香原料,采用改进的Koenigs-knorr法立体选择性的合成了薄荷醇-β-D-葡萄糖苷(Menthyl--βD-Glycoside,MGLY);以反相液相色谱法(RP-HPLC)检测并确定最优反应条件。采用硅胶低压柱层析梯度洗脱分离制备样品,产物纯度达到99.2%,综合IR、LC/MS/MS1、H-NMR1、3C-NMR进行结构鉴定,确证制备的产物为薄荷醇糖苷。

薄荷基甲酸薄荷酯的合成研究

首先以薄荷基甲酸与亚硫酰氯为原料,制得薄荷基甲酰氯;然后以薄荷基甲酰氯和L-薄荷醇进行反应,用无水吡啶为溶剂和缚酸剂,一锅法制得薄荷基甲酸薄荷酯。通过单因素实验和正交试验设计确定优化条件为:n(L-薄荷醇)∶n(薄荷基甲酸)=1∶1.5,n(L-薄荷醇)∶n(无水吡啶)=1∶6,反应温度为60℃,搅拌反应3 h,平均收率达83.91%。得到的目标产物经过IR,1HNMR及MS对其结构进行确认,通过感官评价可知薄荷基甲酸薄荷酯具有较好生理凉感,味觉凉感阈值为1.5 mg·L-1,100 mg·L-1的薄荷基甲酸薄荷酯溶液浸渍的滤纸条能在口中维持凉感的持续时间约为20 min。

L-薄荷基-β-D-乳糖苷的合成

为改进L-薄荷醇的热稳定性和水溶性,对其分子结构改造成糖苷化衍生物。以L-薄荷醇和α-乳糖为原料,经过乙酰化、偶联、脱保护三步反应合成了目标化合物L-薄荷基-β-D-乳糖苷(4),总收率达到42.3%。中间产物和目标化合物的结构经过熔点和旋光度的测定、核磁共振、质谱手段表征。热稳定性和溶解性测试结果表明,该化合物4热稳定性高,水溶性强。

碳酸薄荷酯的合成及其在卷烟中的应用

以薄荷醇为原料,合成了烟用潜香物质碳酸薄荷酯.将其加入卷烟中,经评吸表明:气味阈值与薄荷醇的气味阈值相差较小的香味物质能够与薄荷醇拟合成效果较好的碳酸薄荷酯.

1,1’-联萘-2,2’-二酚及其孟基碳酸酯衍生物的手性高效液相色谱

用高效液相色谱法考察了 1,1’ 联萘 2 ,2’ 二酚及其单和双氯代孟基碳酸衍生物等三对手性化合物在 (S) 特 亮氨酸基 (S) 1 (α 萘基 )乙胺脲型手性色谱柱上的拆分行为 .讨论了三元流动相中 1,2 二氯乙烷和乙醇含量的变化以及不同极性调节剂对分离的影响 ,探讨了这些手性化合物在脲型手性固定相上的可能拆分机理 .该法已用于 ( ) 孟基氯代碳酸酯化学拆分外消旋 1,1’ 联萘 2 ,2’

固体超强酸SO_4^(2-)/ZrO_2催化合成乳酸薄荷酯

介绍了首次采用ＳＯ２－４／ＺｒＯ２催化合成乳酸薄荷酯及反应条件对酯化反应的影响

吡唑醚菌酯和甲基硫菌灵复配对辣椒炭疽病的保护和治疗效果

采用胶孢炭疽病菌孢子悬浮液(1×105个·m L^(-1))针刺接种辣椒感病品种福湘5号的成熟果实,对吡唑醚菌酯与甲基硫菌灵两种单剂及其复配混合物(吡唑醚菌酯与甲基硫菌灵质量比为1︰2,1︰4,1︰8,1︰16和1︰32)的保护与治疗效果进行评价。结果表明:吡唑醚菌酯浓度≥3.00mg·L^(-1)时,它的保护和治疗效果在接种前和接种后施药的平均防治效果能达到81.82%以上;甲基硫菌灵浓度≥16.67mg·L^(-1)时,它的保护和治疗平均防治效果也在81.82%以上;在吡唑醚菌酯∶甲基硫菌灵的5个不同配比中,质量比为1∶8的混合物的保护和治疗作用平均防效最好,当浓度≥3.33mg·L^(-1)时,其平均保护效果达83.12%以上,平均治疗效果在77.92%以上。