Pub Date : 2002-02-10DOI: 10.1246/NIKKASHI.2002.251
有亮 山崎, 順三 正本
We found a novel ring-expansion reaction of 1,3-dioxacycloheptane with ethylene oxide to form 1,4,7,10-tetraoxacyclotetradecane. The reaction is thought to be composed of the following three steps: first, formation of an active intermediate from 3 mol of ethylene oxide and 1 mol of 1,3-dioxacycloheptane; second, elimination of formaldehyde from the intermediate; and finally, cyclization to form 1,4,7,10-tetraoxacyclotetradecane. The relation between the ring size and the ring strain energy is thought to be deeply involved in a significant factor in this novel reaction.
{"title":"1,3-ジオキサシクロヘプタンとエチレンオキシドとの新規環拡大反応による1,4,7,10-テトラオキサシクロテトラデカンの生成","authors":"有亮 山崎, 順三 正本","doi":"10.1246/NIKKASHI.2002.251","DOIUrl":"https://doi.org/10.1246/NIKKASHI.2002.251","url":null,"abstract":"We found a novel ring-expansion reaction of 1,3-dioxacycloheptane with ethylene oxide to form 1,4,7,10-tetraoxacyclotetradecane. The reaction is thought to be composed of the following three steps: first, formation of an active intermediate from 3 mol of ethylene oxide and 1 mol of 1,3-dioxacycloheptane; second, elimination of formaldehyde from the intermediate; and finally, cyclization to form 1,4,7,10-tetraoxacyclotetradecane. The relation between the ring size and the ring strain energy is thought to be deeply involved in a significant factor in this novel reaction.","PeriodicalId":19311,"journal":{"name":"Nippon Kagaku Kaishi","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81191361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-02-10DOI: 10.1246/NIKKASHI.2002.247
正幸 野村, 政夫 加藤, 寛次 佐藤, 信夫 安倍
6-Acetyl-2,2-dimethyl-4-chromanone(6), isolated from Tussilago farfara LINN., was prepared by oxidation of 6-ethyl-2,2-dimethyl-4-chromanone(4) using chromium(VI) oxide in acetic anhydride and acetic acid. The compound 4 was obtained, via the intermediate of ester 3, by condensation of p-ethylphenol and 3-methylcrotonic acid using diphosphorus pentaoxide in polyphsphoric acid. The conversion of 3 to 4 also proceeds efficiently by stirring of the reaction mixture with glass globes in the absence of diphosphorus pentaoxide.
{"title":"漢薬款冬花に含まれる6-アセチル-2,2-ジメチル-4-クロマノンの合成","authors":"正幸 野村, 政夫 加藤, 寛次 佐藤, 信夫 安倍","doi":"10.1246/NIKKASHI.2002.247","DOIUrl":"https://doi.org/10.1246/NIKKASHI.2002.247","url":null,"abstract":"6-Acetyl-2,2-dimethyl-4-chromanone(6), isolated from Tussilago farfara LINN., was prepared by oxidation of 6-ethyl-2,2-dimethyl-4-chromanone(4) using chromium(VI) oxide in acetic anhydride and acetic acid. The compound 4 was obtained, via the intermediate of ester 3, by condensation of p-ethylphenol and 3-methylcrotonic acid using diphosphorus pentaoxide in polyphsphoric acid. The conversion of 3 to 4 also proceeds efficiently by stirring of the reaction mixture with glass globes in the absence of diphosphorus pentaoxide.","PeriodicalId":19311,"journal":{"name":"Nippon Kagaku Kaishi","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79171762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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