[GRAPHICS]Cerium(III) chloride heptahydrate and sodium iodide in boiling acetonitrile promote cyclization of 3-hydroxyalkenoic acids esters giving 5-substituted tetrahydrofuranacetic acid esters and 6-substituted tetrahydropyranacetic acid esters in fair to good yield and with complete retention of the absolute configuration of the starting 3-hydroxy ester.
Au-Catalyzed Cyclization of Monoallylic Diols
作者:Aaron Aponick、Chuan-Ying Li、Berenger Biannic
DOI:10.1021/ol703002p
日期:2008.2.1
The Ph3PAuCl/AgOTf-catalyzed cyclization of monoallylic diols to form tetrahydropyrans is reported. The reactions proceed rapidly at temperatures as low as -78 degrees C with catalyst loadings as low as 0.1 mol % to provide the products in 79-99% yield. A broad range of structurally diverse substrates perform well in the reaction. When 2,6-disubstituted tetrahydropyrans are produced, the reaction is highly diastereoselective for the 2,6-cis product.
HANESSIAN, STEPHEN;DHANOA, DALJIT S.;BEAULIEU, PIERRE L., CAN. J. CHEM., 65,(1987) N 8, 1859-1866
作者:HANESSIAN, STEPHEN、DHANOA, DALJIT S.、BEAULIEU, PIERRE L.
DOI:——
日期:——
Hanessian, Stephen; Dhanoa, Daljit S.; Beaulieu, Pierre L., Canadian Journal of Chemistry, 1987, vol. 65, p. 1859 - 1866
作者:Hanessian, Stephen、Dhanoa, Daljit S.、Beaulieu, Pierre L.