A Simple Synthetic Method for Fluorine-containing 4H-Pyrano[3,2-d]isoxazoles and 4-Cyanoethylisoxazoles from 5-Trifluoroacetyl-2-methoxy-3,4-dihydro-2H-pyran with Hydroxylamine Hydrochloride
摘要:
5-Trifluoroacetyl-2-methoxy-3,4-dihydro-2H-pyran (1), prepared from 2-methoxy-3,4-dihydro-2H-pyran with trifluoroacetic anhydride, reacted cleanly with hydroxylamine hydrochloride in alcohol to give fluorine-containing 4H-pyrano[3,2-d]isoxazoles (2a-g) or 4-cyanoethyldihydroisoxazoles (3) selectively in moderate to high yields. Further conversion of 3 into 4-cyanoethylisoxazoles (4) was also described.
An Efficient Synthesis of Oxa- and Aza-Condensed Tetrahydropyridines from Cyclic Enones
作者:Nilo Zanatta、Liana da Fernandes、Sinara München、Helena Coelho、Simone Amaral、Leonardo Fantinel、Hélio Bonacorso、Marcos Martins
DOI:10.1055/s-0029-1218779
日期:2010.7
A simple and efficient one-pot synthesis of tetrahydrooxazolo[3,2-a]pyridines and hexahydroimidazo[1,2-a]pyridines, and some related oxa- and aza-condensed tetrahydropyridines, from the reaction of 2-alkoxy-5-(trifluoroacetyl)-2,3-dihydro-2H-pyrans (cyclic enones) with amino alcohols and primary diamines, is reported. Products were isolated with highpurity and in very good yields. tetrahydropyridines
一种简单有效的一锅合成方法,是通过2-烷氧基-5-的反应合成四氢恶唑并[3,2- a ]吡啶和六氢咪唑并[1,2- a ]吡啶,以及一些相关的氧杂和氮杂缩合的四氢吡啶。报道了具有氨基醇和伯二胺的(三氟乙酰基)-2,3-二氢-2 H-吡喃(环状烯酮)。分离出的产品具有很高的纯度,并且产率很高。 四氢吡啶-恶唑烷吡啶-咪唑并吡啶-二氢吡喃-环烯酮
Synthesis of 1-Arylethyl-2-arylethylamino-5-trifluoroacetyl-1,2,3,4-tetrahydropyridines and Related Compounds with Potential Cell Efflux Pump Inhibition
作者:Nilo Zanatta、Marcio M. Lobo、Josiane M. dos Santos、Laura de A. Souza、Valquiria P. de Andrade、Helio G. Bonacorso、Marcos A. P. Martins
DOI:10.1002/jhet.2271
日期:2015.11
This study reports a simple, fast, and efficient method for the synthesis of a new series of 1‐arylethyl‐2‐arylethylamino‐5‐trifluoroacetyl‐1,2,3,4‐tetrahydropyridines and relatedcompounds from the reaction of 2‐alkoxy‐5‐trifluoroacetyl‐3,4‐dihydro‐2H‐pyrans with 2‐arylethanamines and related 2‐ethanamines. The desired tetrahydropyridines were obtained in excellent yields (90–98%), through a reaction
Reaction of Benzyl Grignard Reagents with Trifluoroacetyldihydropyrans and Other Cyclic β-Alkoxy-α,β-Unsaturated Trifluoromethylketones
作者:Simon J Coles、John M Mellor、Afaf H El-Sagheer、Ezz El-Din M Salem、Reda N Metwally
DOI:10.1016/s0040-4020(00)00976-5
日期:2000.12
Benzyl Grignard reagents react with cyclic β-alkoxy-α,β-unsaturated trifluoromethyl ketones by 1,2-addition to afford unsaturated allylic alcohols in high yield. The factors determining the balance between 1,2- and 1,4-addition to unsaturated ketones are discussed. The structures of major and minor products are established by single crystal X-ray diffraction studies.
Reaction of Alkyl and Aryl Grignard Reagents with Trifluoroacetyldihydropyrans and Other Cyclic β-Alkoxy-α,β-unsaturated Trifluoromethylketones
作者:John M Mellor、Gill Reid、Afaf H El-Sagheer、El-Sayed H El-Tamany
DOI:10.1016/s0040-4020(00)00975-3
日期:2000.12
β-unsaturated trifluoromethylketones by 1,4-addition to give as the major products, for example, cis-2,3-disubstituted tetrahydropyrans. In most examples ring opening leads to stereoselective formation of rearranged hemiketals as minor products. Under other conditions with 2,2,2-trifluoro-1-(2-ethoxy-3,4-dihydro-2H-5-pyranyl)-1-ethanone stereoselective ring opening leads to acyclic aldehydes, as minor products
烷基和芳基格氏试剂通过加成1,4-与环状β-烷氧基-α,β-不饱和三氟甲基酮反应生成主要产物,例如,顺式-2,3-二取代的四氢吡喃。在大多数例子中,开环导致作为次要产物的重排半酮的立体选择性形成。在其他条件下,带有2,2,2-三氟-1-(2-乙氧基-3,4-二氢-2 H -5-吡喃基)-1-乙酮的立体选择开环会生成无环醛,作为次要产物,并通过通过添加更多当量的格利雅试剂,是通往一系列二醇的主要途径。在较高温度下不存在其他格氏试剂的情况下,内部氢化物转移可提供无环酯。
The importance of A-strain in the stereochemical control of ring opening of tetrahydropyrans
作者:John M Mellor、Afaf H El-Sagheer
DOI:10.1016/s0040-4039(00)01256-9
日期:2000.9
Readily available cyclic beta-alkoxy-alpha,beta-unsaturated trifluoromethylketones react with excess phenyl magnesium bromide by initial 1,4-addition, followed by ring opening to give a variety of products. Both the major products, unsaturated diols, and the minor products, as shown by X-ray diffraction studies, are generated with high stereoselectivity, which is attributed to A(1,3)-strain. (C) 2000 Published by Elsevier Science Ltd.