(-)-1R,2S,5R-8-(4-甲氧基甲基苯)薄荷醇的合成表征

以R-( )-长叶薄荷酮为起始原料,经1,4-加成、还原两步反应合成了手性辅助试剂(-)-1R,2S,5R-8-(4-甲氧基甲基苯)薄荷醇及其反向异构体( )-1S,2S,5R-8-(4-甲氧基甲基苯)薄荷醇,总产率88%.其结构用 1HNMR和 13CNMR进行了表征.     

(1S,2S,5R)-1-苯基薄荷醇的合成

L-薄荷醇经Jones试剂氧化制得L-薄荷酮(1),将L-薄荷酮与苯基锂试剂反应制得产物(1S,2S,5R)-1-苯基薄荷醇(2),其结构经1HNMR,13CNMR,IR以及元素分析进行了表征。分析了影响反应的因素和分离纯化方法,研究结果表明,以投料比n(L-薄荷酮)∶n(苯基锂)∶n(无水乙醚)=0.08∶0.10∶0.76,在-40℃、氮气保护机械搅拌下反应8h,高收率(65%)合成了目标产物2。     

（-）-1R，2S，5R-8-（4-甲氧基苯）薄荷醇的合成表征

以R-( )-长叶薄荷酮为起始原料,经1,4-加成、还原两步反应合成了手性辅助试剂标题化合物及其差向异构体( )-1S,2S,5R-8-(4-甲氧基苯)薄荷醇,总产率83%.其结构经1HNMR和 13CNMR进行了表征.     

乙酰阿魏酸薄荷醇酯的合成与表征

以香兰素和乙酸酐为原料、无水乙酸钠为催化剂,采用Perkin反应合成乙酰阿魏酸,再与氯化亚砜反应合成乙酰阿魏酰氯后,以三聚磷酸钠为缚酸剂与薄荷醇反应合成标题化合物,收率78.5%。采用FT-IR、~1HNMR、~(13)CNMR、元素分析、MS对目标化合物进行表征并确认产物的结构。     

微波辐射下5-(1-氧基)-2(5H)-呋喃酮的合成

研究在微波辐射条件下,以手性助剂天然薄荷醇与5-羟基-2(5H)-呋喃酮反应,合成5-(1-氧基)-2(5H)-呋喃酮.获得了微波的功率40%、反应时间100min、苯为溶剂,薄荷醇/5-羟基-2-(5H)呋喃酮为1/1.7,产率78.6%的好结果.     

左旋溴化N-丁基-4-吡啶甲酸薄荷醇酯离子液体合成方法的研究

以异烟酸、(-)-薄荷醇、溴代正丁烷为原料采用两种不同路线合成了标题化合物,并通过IR、1HNMR、13CNMR等手段进行表征。研究发现,酯化后再季铵化获得手性离子液体的方法优于先季铵化后酯化,该方法合成标题化合物总收率75.2%。     

微波辐射下5-(1-氧基)-2(5H)-呋喃酮的合成

研究在微波辐射条件下 ,以手性助剂天然薄荷醇与 5 -羟基 -2 (5 H ) -呋喃酮反应 ,合成 5 -(1 -氧基 ) -2 (5 H ) -呋喃酮。获得了微波的功率 40 %、反应时间 1 0 0 min、苯为溶剂 ,薄荷醇 /5 -羟基 -2 -(5 H )呋喃酮为 1 /1 .7,产率 78.6%的好结果     

左旋薄荷醇合成技术的进展

薄荷醇是一种用途很广的环状单萜烯醇 ,其合成原料有天然旋光性化合物和非旋光的石油化学品。讨论了薄荷醇的几种合成方法 ,提出了利用异戊二烯为原料合成薄荷醇是今后生产薄荷醇的主要路线     

L-薄荷醇的合成

L-薄荷醇广泛应用于香烟、化妆品、牙膏、口香糖、甜食清凉饮料、医药行业。以薄荷醇为底物合成薄荷醇的衍生物具有重要用途,合成的薄荷醇因质量稳定、价格便宜得到下游客户的认可,特别是合成领域的重视。文章介绍了两种合成L-薄荷醇的合成方法,进行比较后确认通过α-蒎烯合成薄荷醇总体步骤较多,但原料充足易得价格低廉,总收率达到30%,具有良好的工业化方法应用前景。     

拉米夫定的合成

研究了新一代嘧啶核苷类抗病毒药物拉米夫定的合成方法,以L-薄荷醇和乙醛酸为原料,合成L-薄荷醇乙醛酸酯为手性源,经酯化、环合、氯代、缩合、还原5步反应制得目标产物。在乙醛酸-L-薄荷酯(MGH)合成过程中,L-薄荷醇和乙醛酸的最佳摩尔比为3∶1;用双(三氯甲基)碳酸酯代替二甲基亚砜作氯代试剂制备(2R,5S)-5-(胞嘧啶-1′-基)-[1,3]-氧硫杂环戊烷-2-羧酸-L-薄荷酯(NA),收率为60.3%;利用硼氢化钠-甲醇-四氢呋喃体系还原NA,反应4h得到拉米夫定,收率84.8%。产品总收率30.9%,并通过IR、MS等方法对化合物进行了结构表征。     

(-)-1R,2S,5R-8-(4-溴苯)薄荷醇的合成与表征

以R-( )-长叶薄荷酮为起始原料,经1,4-加成、还原、溴代、水解等4步反应合成了标题化合物,总产率77%。其结构用1HNMR、13CNMR和IR进行了表征。     

凉味剂左旋薄荷酰胺的合成

凉味剂WS 3 (即N 乙基 L 薄荷基甲酰胺 )可以左旋薄荷醇为原料 ,经氯代、羧酸化和酰胺化三步制成 ,以左旋薄荷醇为起始原料计 ,总产率为 3 0 .1 %。中间体 ( 1R ,2S ,5R) ( ) 氯代薄荷、( 1R ,2S ,5R) ( ) 薄荷基羧酸、( 1R ,2S ,5R) ( ) 薄荷基羧酸酰氯和终产品N 乙基 L 薄荷基甲酰胺通过GC、m .p.、旋光度的测定及红外光谱等分析确证其与目标产物结构一致。左旋的凉味剂WS 3凉味纯正强烈 ,无杂味。     

龙眼核中的神经酰胺和脑苷脂的分离和鉴定

研究龙眼(Dimocarpus longan Lour.)果核的化学成分,采用硅胶柱色谱对龙眼果核石油醚提取物和体积分数95%乙醇提取物进行分离,并利用理化性质和光谱数据鉴定化合物的结构。从龙眼果核的提取物中分离得到一组混合神经酰胺(化合物1、2)和一组混合脑苷脂(化合物3～6),结构鉴定为Rel-(3S,4S,5S)-3-[(2'R)-2'-羟基二十二酰胺]-4-羟基-5-[(4″Z)-十四烷-4″-烯]-2,3,4,5-四氢呋喃(1)、Rel-(3S,4S,5S)-3-[(2'R)-2'-羟基二十四酰胺]-4-羟基-5-[(4″Z)-十四烷-4″-烯]-2,3,4,5-四氢呋喃(2)、1-O-(β-D-吡喃葡萄糖基)-(2S,3S,4R,8E)-2-(2'-羟基二十四酰胺)-8-十八烯-1,3,4-三醇(3)、1-O-(β-D-吡喃葡萄糖基)-(2S,3S,4R,8Z)-2-(2'-羟基二十四酰胺)-8-十八烯-1,3,4-三醇(4)、1-O-(β-D-吡喃葡萄糖基)-(2S,3S,4R,8E)-2-(2'-羟基二十二酰胺)-8-十八烯-1,3,4-三醇(5)、1-O-(β-D-吡喃葡萄糖基)-(2S,3S,4R,8Z)-2-(2'-羟基二十二酰胺)-8-十八烯-1,3,4-三醇(6)。     

新型手性伪麻黄碱衍生物的合成

首次利用单一构型的伪麻黄碱作为亲核试剂与手性5-(S)-烷氧基-3,4-二卤-2-(5H)-呋喃酮在室温下反应,合成了4种新的单一构型的含手性中心的伪麻黄碱衍生物,产率68%~85%。这是对以往相关研究作了进一步的补充,使得麻黄碱和手性5-(S)-烷氧基-3,4-二卤-2-(5H)-呋喃酮反应体系的工作趋于完善。所有化合物均经IR、1HNMR、13CNMR、HRMS确证,为室温下方便地制备含单一构型的手性伪麻黄碱衍生物提供了一条新途径,也为新型麻黄碱类药物的开发打下基础。     

气相色谱法定量测定牙膏中的薄荷醇、丙二醇和甘油

建立了同时测定牙膏中薄荷醇、丙二醇和甘油含量的气相色谱法。以无水乙醇为溶剂在超声辅助下对8种牙膏样品进行预处理,采用6820型气相色谱仪,配19091X-233 WAX极性毛细管柱(30 m×250μm×0.25μm)进行测定。结果表明,检测的标准偏差为0.17～1.15 mg,平均回收率为89.5%～94.4%。     

肉桂酰胺衍生物的合成与抗菌活性

为了寻找抗菌候选化合物，在前期研究基础上，对蛇床子素结构进行简化与衍生，在甲醇钠/无水乙醇条件下水解，得到(E)-2-羟基-3-异戊烯基-4-甲氧基肉桂酸（Ⅰ），中间体Ⅰ再与胺缩合制备了17个目标物（Ⅱa～q），经1HNMR、13CNMR和MS对目标物进行了结构确证。体外抗菌活性测试结果表明，结构简化后的衍生物呈现较好的抗菌活性。其中，化合物Ⅱh[(E)-3-(2-羟基-4-甲氧基-3-异戊烯基)苯基-N-(4-氟苄基)丙烯酰胺]和Ⅱp[(E)-3-(2-羟基-4-甲氧基-3-异戊烯基)苯基-N-(4-三氟甲基苄基)丙烯酰胺]的活性最为突出，前者对金黄色葡萄球菌（S. aureus）和耐甲氧西林金黄色葡萄球菌（MRSA）的最小抑菌浓度（MIC）分别为16和32 mg/L，后者对S. aureus和MRSA的MIC分别为8和16 mg/L，两个化合物的抗S. aureus活性与对照药苯唑西林较接近，抗MRSA活性远优于对照药苯唑西林。     

L-乳酸薄荷酯的合成

以薄荷醇和L-乳酸为原料,用环已烷带水、经酯化、精制得到L-乳酸薄荷酯,并研究了反应时间、醇酸摩尔比、催化剂量对反应的影响,确定的优惠工艺条件为:n(薄荷醇)∶n(L-乳酸)=1.2∶1.0,催化剂为原料总重量2%,环己烷加热回流带水,反应6h,减压蒸馏至120℃/400Pa。残余物重结晶,得白色针状结晶产品,收率80%以上,纯度达到99%。     

Enzymatic esterification of DL‐menthol with propionic acid by lipase from Candida cylindracea

This work deals with the resolution of DL ‐menthol with propionic acid by Candida cylindracea lipase (Ccl) in organic solvent reaction systems and a reverse micelles system of sodium 1,4‐bis (2‐ethylhexyl) sulfosuccinate (AOT). The activity and stability as well as enantioselectivity of the lipase in two systems were studied. The results indicate that the lipase showed higher stability in reverse micelles than in organic solvent, which proved that the reverse micelles system has potential application for maintaining the activity of the enzyme for a long time. This is because lipase molecules can be entrapped in water‐containing micro‐drops of reverse micelles, avoiding direct‐contract with unfavorable organic medium. The enantioselectivity (E > 30, ee_p = 92.5) in the two systems is relatively high, although the conversion is moderate. The influence of the characteristic parameters of the two systems, such as pH, temperature, w₀ (molar ratio of water to AOT in reverse micelles systems) and water content (organic solvent) on the conversion of DL ‐menthol was also investigated. Copyright © 2005 Society of Chemical Industry     

Semiochemistry of the Goldeneyed Lacewing Chrysopa oculata: Attraction of Males to a Male-Produced Pheromone

Gas chromatographic-electroantennographic detection (G3C-EAD) experiments showed that antennae of males and females of the goldeneyed lacewing, Chrysopa oculata Say (Co. = Chrysopa), consistently responded to four compounds extracted from the abdominal cuticle of males:nonanal, nonanol, nonanoic acid, and (1R*,2S*,5R*,8R*)-iridodial. These compounds were not detected from abdominal cuticle of females. Thoracic extracts of both sexes contained antennal-stimulatory 1-tridecene and EAD-inactive skatole. Chrysopa oculata adults were most sensitive to (1R,2S,5R,8R)-iridodial standard at an EAD-response threshold between 0.1 and 1 pg, which was 10-100 times lower than thresholds for nonanal and nonanoic acid, and up to 10,000 times lower than thresholds for other compounds tested. A similar EAD response pattern was also found in another Chrysopa sp. (Co. quadripunctata Burmeister). In field-trapping experiments, (1R,2S,5R,8R)-iridodial was the only male-specific compound that attracted Co. oculata males. Males also were weakly attracted to (1R,4aS,7S,7aR)-nepetalactol (an aphid sex pheromone component), probably due to the 5% (1R,2S,5R,8R)-iridodial present in the synthetic sample as an impurity. A herbivore-induced plant volatile, methyl salicylate, increased attraction of males to (1R,2S,5R,8R)-iridodial, whereas 1-tridecene was antagonistic. No females were caught in the entire study. Scanning electron micrographs revealed numerous male-specific, elliptical epidermal glands on the 3rd-8th abdominal sternites of Co. oculata, which are likely the pheromone glands. Another lacewing species, Chrysoperla rufilabris (Burmeister) (Cl. = Chrysoperla), did not produce male-specific volatiles or possess the type of gland presumed to produce pheromone in Co. oculata males, but (Z)-4-tridecene was identified as a major antennal-stimulatory compound from thoracic extracts of both sexes of Cl. rufilabris. Thus, (1R,2S,5R,8R)-iridodial (or its enantiomer) is now identified as a male-produced male aggregation pheromone for Co. oculata, the first pheromone identified for lacewings.