An iodine‐mediated oxidative ring contraction of cyclobutanols has been developed. The reaction allows the synthesis of a wide range of aryl cyclopropyl ketones under mild and eco‐friendly conditions. A variety of functional groups including aromatic or alkyl halides, ethers, esters, ketones, alkenes, and even aldehydes are nicely tolerated in the reaction. This is in contrast with traditional synthetic
Regioselective Electrochemical Cyclobutanol Ring Expansion to 1‐Tetralones
作者:Alessia Petti、Philipp Natho、Kevin Lam、Philip J. Parsons
DOI:10.1002/ejoc.202001535
日期:2021.2.5
A new electrochemical approach to the oxidative ringexpansion of functionalized cyclobutanols is reported. Aryl and heteroaryl 1‐tetralones are synthesized under mild and cost‐efficient conditions. The newly designed methodology proves to be tolerant of a good range of functional groups and its application to larger scale syntheses is shown to be feasible.
A regioselective synthesis of 1-tetralones via silver-catalyzed ringexpansion is described. A variety of 1-tetralones are furnished under mild reaction conditions from tertiary cyclobutanols regardless of the electronic properties and steric hindrance of substituents, providing a new and practical method to access diverse 1-tetralone building blocks. Preliminary experimental and DFT studies revealed
A number of ortho-cyclohexenyl phenols 2(a-i) have been cyclised by treatment with one equivalent of m-chloroperoxybenzoic acid in refluxing benzene for 4 h to furnish linearly fused 1-hydroxy-1,2,3,4,4a,9a-hexahydrodibenzofurans 3 (a-i) (70-80%) and bicyclic 3-hydroxy-1,3-ethanochromans 4(a-f) (10-20%). Products 3(a-i) were oxidised with 2,3-dichloro-5,6-dicyano-1 ,4-benzoquinone (excess) in refluxing dry xylene for 6 h to give 2,3-dihydrodibenzofuran-1 (2H)-ones 6(a-i) (85-95%).