Bi(OTf)3-catalysed intramolecular cyclisation of unsaturated acetals. Issue 34 (14th June 2021)

• Record Type: Journal Article
• Authors: Saget, Raphaël; Jaunky, Piotr; Duñach, Elisabet
• Is Part Of: RSC advances. Volume 11:Issue 34(2021)
• Page Start: 21066
• Page End: 21072
• Publication Date: 2021-06-14
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d1ra03686f
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : A series of highly functionalized carbocycles was efficiently prepared via the selective cyclisation of unsaturated acetals and ketals in the presence of only 1 mol% of Bi(iii ) or Fe(iii ) triflates as the catalysts at room temperature, with yields ranging from 60 to 90%. Abstract : A series of highly functionalized carbocycles was efficiently prepared via the selective cyclisation of unsaturated acetals and ketals in the presence of only 1 mol% of Bi(iii ) or Fe(iii ) triflates as the catalysts at room temperature, with yields ranging from 60 to 90%. With Bi(OTf)3 catalysis, α, β-unsaturated ether carbocycles are formed selectively, whereas with the Fe(OTf)3 system, a cycloisomerisation to carbocyclic diethers is mainly obtained. This acetal/olefin cyclisation could be run at a multi-gram scale and compound 2c could be obtained on a 300 gram-scale with a yield of 69% after precipitation in hexane.