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Dharma R. Kodali David Atkinson Trevor G. Redgrave Donald M. Small 《Journal of the American Oil Chemists' Society》1984,61(6):1078-1084
Stereospecific 1,2-dipalmitoyl-sn-glycerol and 1,2-dipalmitoyl-3-acyl-sn-glycerols with even-carbon saturated fatty acyl chains of 2–16 carbons in length were synthesized. The polymorphic behavior
and packing arrangements of the most stable crystal form obtained, from the solvent of crystallization, were studied by differential
scanning calorimetry and powder X-ray diffraction. Three different layered packing modes were identified: (a) double-layer
diglyceride-type; (b) triple-layer triglyceride-type; (c) double-layer triglyceride-type. The first type of packing was represented
by 1,2-dipalmitoyl-3-unsubstituted, 3-acetyl and 3-butyryl-sn-glycerols packed in a bilayer with their long hydrocarbon chains in a parallel arrangement. In the second type of packing,
shown by 1,2-dipalmitoyl 3-hexanoyl and 3-octanoyl-sn-glycerols, the shorter acyl chains formed a middle layer interposed between 2 layers of the 1,2-palmitoyl chains ofsn-glycerol. The third type of crystal packing was exhibited by 1,2-dipalmitoyl-3-dodecanoyl and 3-tetradecanoyl-sn-glycerols and tripalmitin, was analogous to trilaurin in which the acyl chains at the 1 and 2 positions of glycerol formed
an extended, nearly straight line and the 3-acyl chain was folded to lie parallel and alongside the acyl chain at the 1 position.
The intermediate member of the series, 1,2-dipalmitoyl-3-decanoyl-sn-glycerol, exhibited both the second and the third type of chain packings when obtained from different solvents of crystallization.
This work was presented in part at the Indian Science Congress Association, Tirupati, India, 1983. 相似文献
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3-氯-1,2-丙二醇及缩水甘油的合成研究 总被引:2,自引:0,他引:2
以甘油为原料,在无水乙酸的作用下与HCl反应合成出3-氯-1,2-丙二醇,优化了3-氯-1,2-丙二醇的合成工艺,得到适宜的反应条件为:反应温度90℃,反应时间4 h,催化剂用量5%(w/w),HCl气体流速20 L/h。然后利用制备的3-氯-1,2-丙二醇在二氯甲烷溶剂中与强碱性阴离子交换树脂作用合成了缩水甘油,最佳反应时间为1 h。产物分别通过GC和IR进行了鉴定,3-氯-1,2-丙二醇和缩水甘油的产率分别可达到84.6%和89.6%。 相似文献
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研究了以高活性Lewis酸无水三氯化铝(AlCl3)为催化剂,蒽和草酰氯为反应物合成1,2-蒽乙二酮的酰基化反应.用GC考察了不同反应条件对1,2-蒽乙二酮产率的影响,当蒽为1 mmol,草酰氯为2 mmol,AlCl3为4 mmol,溶剂为CS2(15 mL),反应温度为30 ℃,反应时间5 h的条件下,1,2-蒽乙二酮的产率最高,为83.8%.通过萃取、重结晶等方法得到了 1,2-蒽乙二酮纯品,用熔点测定、GC/MS、FT-IR和 1HNMR等分析测试手段鉴定了其结构. 相似文献
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研究了一种以2,2’-二硫代苯甲酸为原料,用双(三氯甲基)碳酸酯替代氯化亚砜进行酰氯化反应制得2,2’-二硫代苯甲酰氯,然后在氨溶液中通空气进行歧化环合制得抑菌剂1,2-苯并异噻唑啉-3-酮(BIT)的合成方法,该方法操作方便,具有工业化应用前景。研究讨论了影响反应的多种因素并得到比较合理的工艺条件,总收率达78.2%。对产品结构进行了1 H NMR表征确认。 相似文献
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以1,2-二溴乙烷和苯酚为原料,KOH水溶液为溶剂,采用相转移催化法和分步加碱法,合成1,2-二苯氧基乙烷。探讨了反应物质的投料比、催化剂的种类、反应温度及回流时间等对收率的影响,确定了1,2-二苯氧基乙烷合成的最佳工艺。当n(苯酚)∶n(1,2-二溴乙烷)=1∶2,n(苯酚)∶n(KOH)=1∶2,加入聚乙二醇PEG-1000作为相转移催化剂,80~90℃回流反应20 h,120℃浓缩分水使反应完全,产率可达90.60%。采用了GC-MS、~1H NMR,熔点测定等对产物进行了分子结构与相关性能的表征。优化1,2-二苯氧基乙烷的合成工艺,为工业生产提供依据。 相似文献
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研究了11种催化剂对1,2 双(3 甲氧羰基 2 硫脲基)苯的合成性能的影响,筛选得出催化剂(对氨基二甲苯胺∶N,N 二甲基苯胺∶N,N 二甲基十八胺=1∶6∶3,质量比),在所给定的反应条件下(催化剂用量为反应物总质量的2%,时间60min,温度25~35℃),可使产物收率(相对邻苯二胺)达88%以上,纯度达98%以上。 相似文献