The invention relates to novel cyclopenteno[b]pyridine derivatives which have a group X on the 7-position and related tricyclic compounds. X is CONHR.sup.3, or CO.sub.2 R.sup.5 wherein R.sup.3 is hydrogen or lower alkyl and R.sup.5 is hydrogen or a lower alkyl or lower aralkyl group which may be substituted by alkyl, alkoxy, halogen, nitro or trifluoromethyl; other substituents may be present. The compounds are intermediates for compounds wherein X is CSNHR.sup.3 which are anti-ulcer agents.
Superbase-Promoted Selective Cascade Cyclization Reaction of 1,5-Diketones with Acetylenes to Methylene-6,8-dioxabicyclo[3.2.1]octanes
作者:Elena Yu. Schmidt、Ivan A. Bidusenko、Nadezhda I. Protsuk、Igor A. Ushakov、Boris A. Trofimov
DOI:10.1002/ejoc.201201700
日期:2013.4
1,5-Diketones are readily cyclized in the presence of various alkali-metal superbases with acetylenes at 70 °C in a one-pot cascade reaction to give methylene-6,8-dioxabicyclo[3.2.1]octanes in up to 92 % yield. In the case of symmetrical 1,5-diketones, only one diastereomer is formed, whereas unsymmetrical diketones afford two diastereomers in a ratio corresponding to that of the starting ketones.
1,5-二酮在各种碱金属超强碱存在下与乙炔在 70 °C 的一锅级联反应中很容易环化,得到高达 92% 的亚甲基-6,8-二氧杂双环 [3.2.1] 辛烷屈服。在对称的 1,5-二酮的情况下,仅形成一种非对映异构体,而不对称的二酮以对应于起始酮的比例提供两种非对映异构体。该结果表明关键的级联环化序列是立体选择性的。
CONDENSATION OF ALICYCLIC KETONES WITH UREA AND THIOUREA
作者:A. F. McKay、C. Podesva、E. J. Tarlton、J.-M. Billy
DOI:10.1139/v64-002
日期:1964.1.1
by the condensation of urea with cyclohexanone, has been confirmed by equilibration in the presence of potassium t-butoxide. The failure of 4-t-butylcyclohexyl 2-carbamyl-4-t-butylcyclohexylamine to equilibrate under the same conditions is discussed in relation to its structure. 1,2,3,4,5,6,7,8-Octahydroacridine was prepared by the condensation of 2,2′-methylene-bis-cyclohexanone with urea.
Stereoelectronic Control in the Ozone‐Free Synthesis of Ozonides
作者:Gabriel dos Passos Gomes、Ivan A. Yaremenko、Peter S. Radulov、Roman A. Novikov、Vladimir V. Chernyshev、Alexander A. Korlyukov、Gennady I. Nikishin、Igor V. Alabugin、Alexander O. Terent'ev
DOI:10.1002/anie.201610699
日期:2017.4.24
The value of stereoelectronic guidelines is illustrated by the discovery of a convenient, ozone‐free synthesis of bridged secondary ozonides from 1,5‐dicarbonyl compounds and H2O2. The tetraoxane products generally formed in reactions of carbonyl and dicarbonyl compounds with H2O2 were not detected because the structural distortions imposed on the tetraoxacyclohexane subunit in [3.2.2]tetraoxanonanes
立体电子指导原则的价值通过发现一种由1,5-二羰基化合物和H 2 O 2方便,无臭氧合成桥连的次级恶臭化合物的方法来说明。未检测到通常在羰基和二羰基化合物与H 2 O 2反应中形成的四恶烷产物,因为通过三碳桥作用在[3.2.2]四恶烷中的四氧杂环己烷亚基上的结构变形会导致端基异构化作用的部分失活。新程序易于扩展以生产克量的臭氧化物。该反应使得可以在不使用臭氧的情况下选择性制备臭氧化物。
Reactivity of alicyclic 1,5,9-triketones toward five-, six-, and seven-membered rings in acidic medium. Stereochemistry of intramolecular cyclization products
作者:Taisia I. Akimova、Olga A. Soldatkina、Andrey V. Gerasimenko、Vyacheslav G. Savchenko、Alevtina A. Kapustina
DOI:10.1007/s10593-021-03028-9
日期:2021.11
Among nine alicyclic 1,5,9-triketones with differently fused 5-, 6-, and 7-membered rings in the molecule, existing as mixtures of 3–6 diastereomers, only those containing at least two 6-membered rings were capable of intramolecular cyclization in acidic medium (HCl, EtOH). The diastereomer mixture underwent stereoselective transformation, giving one major cyclization product. The relative configuration