Stereoselective Synthesis of δ-Lactones from 5-Oxoalkanals via One-Pot Sequential Acetalization, Tishchenko Reaction, and Lactonization by Cooperative Catalysis of Samarium Ion and Mercaptan
作者:Jue-Liang Hsu、Jim-Min Fang
DOI:10.1021/jo016058t
日期:2001.12.1
sequence of acetalization, Tishchenko reaction and lactonization. The deliberative use of mercaptan, by comparison with alcohol, is advantageous to facilitate the catalytic cycle. The reaction mechanism and stereochemistry are proposed and supported by some experimental evidence. Such samarium ion/mercaptan cocatalyzed reactions show the feature of remote control, which is applicable to the asymmetric synthesis
Surface-mediated solid phase reaction. Mukaiyama-Michael addition of silyl enol ethers to methyl vinyl ketone on the surface of alumina
作者:Brindaban C. Ranu、Manika Saha、Sanjay Bhar
DOI:10.1016/s0040-4039(00)91983-x
日期:1993.3
Clean and efficient Michael addition of silyl enol ethers to methyl vinyl ketone has been achieved through a simple solvent-free reaction on the surfac
Enamines. Part II. The reaction of enamines with methyl vinyl ketone
作者:Ian Fleming、M. H. Karger
DOI:10.1039/j39670000226
日期:——
NN-dimethylisobutenylamine with methyl vinyl ketone gives 2-dimethylamino-3,3,6-trimethyl-3,4-dihydro-2H-pyran as the first formed product. The structure was deduced from extensive spectroscopic examination of the adduct. The chemical reactions of the adduct, however, indicated a ready equilibration of the dihydropyran with methyl 2-dimethylamino-3,3-dimethylcyclobutyl ketone through the immonium enolate
Pfau,M. et al., Bulletin de la Societe Chimique de France, 1979, vol. <II>, p. 627 - 632
作者:Pfau,M. et al.
DOI:——
日期:——
Cooperative Catalysis of Samarium Diiodide and Mercaptan in a Stereoselective One-Pot Transformation of 5-Oxopentanals into δ-Lactones
作者:Jue-Liang Hsu、Chao-Tsen Chen、Jim-Min Fang
DOI:10.1021/ol9911526
日期:1999.12.1
[GRAPHICS]We demonstrate a general method for conversion of various 5-oxopentanals to substituted delta-lactones and 1-oxa-2-decalones by the synergistic catalysis of samarium diiodide and 2-propanethiol (or disulfide), The deliberate use of mercaptan is advantageous to facilitate the catalytic cycle, This method shows high stereoselectivities, and an enantioselective procedure is feasible by using the chiral mercaptan (1R,2S)-1 phenyl-2-(N-acetamido)propanethiol as a promoter.