乙二醛

Dihydroxy-7, 4′-dimethoxy-dihydrflavonol and -3, 5, 7 -trihydroxy-4′-methoxy- dihydrflavonol were synthesized by selective protection, condensation, epoxidation, cyclization and deprotection from 2, 4, 6-trihydroxyacetophone and anisaldehyde.

以2，4，6-三羟基苯乙酮和茴香醛为起始原料，经选择性保护、缩合、环氧化、关环等步骤首次完成了-3，5-二羟基-7，4′-二甲氧基二氢黄酮醇和-3，5，7-三羟基-4′-甲氧基二氢黄酮醇全合成。

We have had the extensive studies on theα-acetyl-α-carbamoyl ketene--acetals and its further applications, for example, their adols condensations with aldehydes giveα-alkenoyl-α-carbamoyl ketene--acetals which can be utilized as the 1,5-bielectronic five-carbon components to react with various binucleophlilic species in a [5+1] annulation.

我们小组在以前的工作中对α-乙酰基-α-胺甲酰基二硫缩烯酮在合成中的应用进行了深入的研究，如与醛缩合生成α-烯酰基-α-胺甲酰基二硫缩烯酮，将其作为1，5-双亲电五碳合成子的[5+1]成环策略等。

In this paper, Claisen condensation of isochroman ?4?one as starting material with diethyl oxalate is carried out to form β?diketone compound of isochroman ?4?one.

以异色满酮 4为起始原料，经Claisen缩合得其β二酮衍生物，再与水合肼进行Knorr反应环合成 3 乙氧甲酰基和 3 肼甲酰基异色满并吡唑衍生物，通过酰肼与糠醛反应成腙后，分别与巯基乙酸和氯乙酰氯反应合成了标题化合物

In this paper, methylal and diethoxymethane were used as end capping agents to improve the thermal stability of the product in molten copolymerization of trioxane with ethylene oxide or with dioxolane.

为此研究了在三聚甲醛与环氧乙烷或三聚甲醛与二氧五环熔融共聚体系中，通过封端剂甲缩醛或二乙氧基甲烷的使用，对热碱稳定的共聚甲醛的收率提高了3％左右。

Water, Kaolin, Montmorillonite, Stearic Acid, Cetyl Alcohol, Glycereth-26, Glyceryl Stearate, Peg-100 Stearate, Aloe Barbadensis Leaf Juice, Triethanolamine, Titanium Dioxide, Menthyl Pca, Lauryl Pca, Fragrance, Diazolidinyl Urea, Propylene Glycol, Ethoxydiglycol, Methylparaben, Citric Acid, Panax Ginseng Root Extract, Zinc Pca, Copper Pca, Yellow 5, Blue 1

水，高岭土，蒙脱土，硬脂酸，鲸蜡醇，Glycereth-26，甘油硬脂酸酯，培格100硬脂酸，芦荟叶汁，三乙醇胺，二氧化钛，薄荷醇，香料，尿素醛，丙二醇，乙氧基二甘醇，对羟基苯甲酸甲酯，柠檬酸，人参精华，锌，铜，黄色5#，蓝色1#。

Bis-imidazoline was prepared from triethylene tetraamine and N,N-dimethylformamide dimethyl acetal at 85℃ for 2 h with toluene as solvent, with a yield of 90.4%. The reaction of bis-imidazoline with 1,2-dibromoethane and potassium carbonate in acetonitrile provided with a monobromide salt yield of 78.7%. Hydrolysis of monobromide salt under aqueous causic solution formed 1,4,7,10-tetraazzcyclododecane in a 74.2% yield.

用甲苯作溶剂，使三乙烯四胺和N，N-二甲基甲酰胺二甲基缩醛在85℃反应2 h，得到中间体双咪唑啉，产率90.4%，在乙腈溶剂中，碳酸钾存在下，双咪唑啉和1，2-二溴乙烷进行扩环反应，得到环状中间体一溴盐，产率78.7%，一溴盐经碱性水解2 h，得到1，4，7，10-四氮杂十二烷，产率74.2%。

The α-monobromination of 2-pentone,4-methyl acetophenone,4-methoxyacetophenone,6-methoxy-2-acetylnaphthane,2,2,5,5-tetramethyl-3-hexanone,cyclooctanone,cyclododecanone with respectively,were studied.

研究了离子液体三溴化1-丁基-3-甲基咪唑[Br3]对2-戊酮、4-甲基苯乙酮、4-甲氧基苯乙酮、6-甲氧基-2-乙酰基萘、2，2，5，5-4-甲基-3-己酮、环辛酮、环十二酮、丁醛等羰基化合物的α-溴化反应。

Aldol condensation 2, 5-dimethoxymethoxyacetophone with 2, 4, 6 -tri methoxymethoxybenzendehyde, then hydrogenation, reductive, the key intermediate 83 (84) of natural product 3, 5, 7, 2′, 5′- pentahydroxyflavan, was obtained; Mini reviewed EGCg activity, Then gallic acid and phloroglucin were used to synthsis EGCg, The key intermediate Chalcone 109 of EGCg was abtained through 7 steps from gallic acid.

重点介绍了以没食子酸为原料，经酯化，保护，还原，氧化，格氏反应，氧化六步反应得到3，4，5-三苄氧基苯乙酮，以间苯三酚为原料，经维斯迈尔反应，苄基保护，甲氧甲氧基保护三步反应得到2，4-二苄氧基-6甲氧甲氧基苯甲醛，酮106与醛108经羟醛缩合得到EGCg重要反应中间体查尔酮109。

Results: Nine compounds were obtained from the ethyl acetate fraction of C. speciosa and were identified as methyl chlorogenate, 5-O-cafeoyl quinic acid butyl ester, quinic acid butyl ester, 5-hydroxymethyl-furan-2-carbaldehyde, triacontanoic acid,-epicatichin, 7,8-dihydroxy-coumanrin, protocatechuic acid ethyl ester, and protocatechuic acid.

结果：从皱皮木瓜的乙酸乙酯萃取部位分离鉴定了9种化合物，分别为绿原酸甲酯，5-O-咖啡酰基－奎宁酸丁酯，奎宁酸丁酯，5-羟甲基－2-糠醛，三十烷酸，-表儿茶素，7，8-二羟基香豆素，3，4-二羟基苯甲酸乙酯，原儿茶酸。

Dihydropyrimidin-2 (1H)-ones were synthesized by condensation of aromatic or aliphatic aldehydes, urea and ethyl acetoacetate or acetylacetone one-pot three-component Biginelli condensation in the presence of room temperature ionic liquids as catalysts under solvent-free conditions.

5利用室温离子液体作催化剂，芳香或脂肪醛、尿素和乙酰乙酸乙酯或乙酰丙酮三组分缩合制备3，4-二氢嘧啶-2-酮衍生物。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。