Unconventional type of allylation reaction at the β-position of ketone carbonyl has been developed based on the β-metallo ketone strategy: treatment of siloxycyclopropanes 1 with allylic chlorides 2 in the presence of silver fluoride results in the effective formation of δ, ε-unsaturated ketones 4.
Stereoselective Synthesis of Substituted Oxocene Cores by Lewis Acid Promoted Cyclization
作者:Arun K. Ghosh、Anthony J. Tomaine、Kelsey E. Cantwell
DOI:10.1021/acs.orglett.5b03411
日期:2016.2.5
Substituted oxocene derivatives have been synthesized by Lewis acid catalyzed reactions of ε-hydroxyalkene and substituted aromatic aldehydes. The Cu(OTf)2-bis-phosphine catalyzed reaction typically provides substituted dihydropyran derivatives through an olefin migration followed by a Prins cyclization. The corresponding reaction catalyzed by TMSOTf or BF3·OEt2 provided eight-membered cyclic ethers