{"title":"Gold(i)-catalysed cyclisation of (E)-ketene-N,O-acetals: a synthetic route toward spiro-oxazole-γ-lactones†‡","authors":"Suresh Kanikarapu , Rangu Prasad , Manoj Sethi , Akhila K. Sahoo","doi":"10.1039/d4ob00551a","DOIUrl":null,"url":null,"abstract":"<div><p>In this study, we developed a cascade 5,5-cyclisation of internal ketene-<em>N</em>,<em>O</em>-acetals utilizing homogeneous Au(<span>i</span>) catalysis. This process involves an initial 5-<em>exo-dig</em> carbocyclisation, followed by a 5-<em>exo-dig</em> heterocyclisation that stereoselectively incorporates the O-atom of a water molecule into an N-tethered propargyl alkyne. This sequential reaction results in the formation of one C–C, two C–O, and two C–I bonds, ultimately leading to the synthesis of spiro-α-iodo-γ-lactone structures featuring oxazole rings in good yields.</p></div>","PeriodicalId":96,"journal":{"name":"Organic & Biomolecular Chemistry","volume":"22 23","pages":"Pages 4672-4679"},"PeriodicalIF":2.7000,"publicationDate":"2024-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Organic & Biomolecular Chemistry","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/org/science/article/pii/S1477052024004683","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/5/20 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"CHEMISTRY, ORGANIC","Score":null,"Total":0}
引用次数: 0
Abstract
In this study, we developed a cascade 5,5-cyclisation of internal ketene-N,O-acetals utilizing homogeneous Au(i) catalysis. This process involves an initial 5-exo-dig carbocyclisation, followed by a 5-exo-dig heterocyclisation that stereoselectively incorporates the O-atom of a water molecule into an N-tethered propargyl alkyne. This sequential reaction results in the formation of one C–C, two C–O, and two C–I bonds, ultimately leading to the synthesis of spiro-α-iodo-γ-lactone structures featuring oxazole rings in good yields.
期刊介绍:
Organic & Biomolecular Chemistry is an international journal using integrated research in chemistry-organic chemistry. Founded in 2003 by the Royal Society of Chemistry, the journal is published in Semimonthly issues and has been indexed by SCIE, a leading international database. The journal focuses on the key research and cutting-edge progress in the field of chemistry-organic chemistry, publishes and reports the research results in this field in a timely manner, and is committed to becoming a window and platform for rapid academic exchanges among peers in this field. The journal's impact factor in 2023 is 2.9, and its CiteScore is 5.5.