Twice annulations of 6, 7-dimethoxy-3, 4-dihydroisoquinoline hydrochloride (7) stereoselectively give the pseudoberbenone (12), the catalytic reduction of which preferentially affords the alloberbanone (15). On a series of reactions (oxidation, O-methylation, sodium borohydride reduction, ether cleavage and catalytic reduction) 12 is converted into the berbanone (25) via the berbadienone (21). Oxidations of 15 and 25 with mercuric acetate smoothly afford the 1, 11-didehydro compounds (17) and (26), respectively. Two isomeric metho salts (18) and (19) obtained from 17, and the one (31) from 21 are found to give the starting materials by demethylation under conditions of the Hofmann degradation. Stereostructures of the compounds obtained here are examined on the basis of the infrared and nuclear magnetic resonance spectra. Their formation pathways are also discussed.
Many reports have indicated that numerous rules can be established as to the relationship detween the chemical structure and activity of curariform substanes. Pharmacological examination of the 20 kinds of compounds of this series synthesized revealed the following results.1) It is a fact that the distance between the quaternary nitrogens is about 15°A but it was found that some variation appears by the manner of the binding bridge.2) It was experimentally recognized that the activity is stronger when the nitrogencontaining ring is saturated than when unsaturated.3) The rule that the activity is stronger when there is a methoxyl group in the nitrogencontaining ring, than when it is a hydroxyl or when there is no substituent was developed further to show that the activity is stronger in one with a methoxyl group than a methylenedioxy group, and in one with a larger number of the methoxyl groups.4) No report has appeared to date regarding stereoisomers but the present experiments revealed that there were no marked differences in stereoisomers as to activity or lethal dose.
Chiral benzo [c] phenanthridines have been synthesized. Aminolysis of the (-)-epoxyhydroxy lactone (3) with methylamine stereospecifically gives the (+)-trihydroxy lactam (5), from which the (+)-10b-hydroxychelidonine (7) and (+)-11-epichelidonine analogs (10) are derived. The absolute configurations of the compounds obtained are assigned on the basis of that of (-)-3 and the results obtained from the subsequent stereocontrolled reactions. The absolute configurations of (+)-7 and (+)-10 are confirmed by Horeau's method.
Abstract Die extrem oxidationsempfindliche Verbindung (I) reagiert mit molekularem Sauerstoff zu einer Epidioxy‐Verbindung (II), die sich mit Natriumborhydrid zum Hexahydrochelerythrin (III) reduzieren läßt. Die Behandlung des Peroxids (II) mit Dichlordicyanbenzochinon (DDQ) führt zu einem Gemisch der vier Verbindungen (IV)‐(VII), deren Bildungsmechanismen diskutiert werden.
An alumina-induced reaction of 6-acetoximino-3β-acetoxycholestan-5α-ol nitrite (I) is examined and affords several kinds of compounds. Among them II, III and IV are belong to the same type of compound. From the spectral data and their reactions, the structures containing 5α, 6α-epoxy and 6β, 7β-isonitrosoimino groups are tentatively assumed for them. V and VI are identified to be another type containing 5α-acetoxy and 6-oxo groups. The formation pathways of both types of compounds are deduced by comparison with the reaction products of the relative compounds.
Abstract Im Gegensatz zu einer früheren Mitteilung entsteht aus (II) mit Ethylenglykol das Furoisocarbostyril (III) und bei azeotroper Destillation des gebildeten Wassers das Ketal (IV).
Abstract Aus (I) und (IX) werden nach den angedeuteten Methoden die beiden in der Synthese von Steroiden bereits früher eingesetzten Ketone (VIII) und (XV) hergestellt.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA New Modified Steroid, Hancopregnane, and a New Monoterpene from Cynanchum hancockianumYaeko Konda, Yumiko Toda, Hiroaki Takayanagi, Haruo Ogura, Yoshihiro Harigaya, Hongxiang Lou, Xian Li, and Masayuki OndaCite this: J. Nat. Prod. 1992, 55, 8, 1118–1123Publication Date (Print):August 1, 1992Publication History Published online1 July 2004Published inissue 1 August 1992https://pubs.acs.org/doi/10.1021/np50086a013https://doi.org/10.1021/np50086a013research-articleACS PublicationsRequest reuse permissionsArticle Views156Altmetric-Citations9LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
In the microbial transformation by Trametes sanguinea, 14β-bromocodeinone (IV) was first converted enzymatically into 14β-bromocodeine (VI), which was gradually affected chemically to form VII, II, and VIII as the final products.
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