73090-02-5Relevant academic research and scientific papers
Use of a semihollow-shaped triethynylphosphane ligand for efficient formation of six- and seven-membered ring ethers through gold(I)-catalyzed cyclization of hydroxy-tethered propargylic esters
Ito, Hideto,Harada, Ayumi,Ohmiya, Hirohisa,Sawamura, Masaya
supporting information, p. 647 - 652 (2013/04/10)
The formation of six- and seven-membered ring ethers from hydroxy-tethered propargylic esters was efficiently catalyzed by a cationic gold(I) complex with a semihollow-shaped triethynylphosphane ligand. This gold catalysis showed a tolerance toward the reactions of primary, secondary, and tertiary alcohol substrates with various substitution patterns. A sterically congested 2,2,6,6-tetraalkyl-substituted tetrahydropyran derivative as well as 6,6- and 7,6-fused bicyclic diethers were obtained in useful yields. In addition, the gold catalysis was applicable to the reaction of a sulfonamide-tethered propargylic ester to give a piperidine derivative. Copyright
One-Step Annelation. A Convenient Method for the Preparation of Diols, Spirolactones, and Spiroethers from Lactones
Canonne, Persephone,Foscolos, Georges B.,Belanger, Denis
, p. 1828 - 1835 (2007/10/02)
1-(ω-Hydroxyalkyl)cyclopentanols and -cyclohexanols were prepared in one step in high yields from butane-1,4-diyl- and pentane-1,5-diylmagnesium dibromides and lactones in tetrahydrofuran.This method was found to be general and applicable to lactones of any size (β, γ, δ, and ε) and structure whether aliphatic, aromatic, bicyclic, or spirocyclic.Evidently important steric hindrance close to the carbonyl group prevents annelation and attack on the second nucleophilic center of the Grignard reagent.Furthermore, in the case of oxetan-2-one one obtains, in additionto the corresponding diol, products resulting from scission of the C-O bond.The diols by appropriate transformation afford new routes to spirolactones and spiroethers.
