Preparation of Oxepanes, Oxepenes, and Oxocanes by Iodoetherification using Bis(sym-collidine)iodine(I) Hexafluorophosphate as Electrophile
摘要:
Oxepanes have been obtained in good yields (40-95%) by iodoetherification of unsaturated alcohols using bis(sym-collidine)iodine(I) hexafluorophosphate (1) as electrophile, either by 7-exo-mode or 7-endo-mode cyclizations. 4-Oxepenes could also be formed from 4,6-heptadien-1-ols; the presence of a substituent on the carbon 6 appeared necessary, while for steric reasons the presence of a substituent on the carbon 7 was unfavorable. Oxocanes could be obtained in moderate yields (18-27%).
LASSALLE, GILBERT;GREE, RENE, C. R. ACAD. SCI. SER. 2, 310,(1990) N, C. 907-911
作者:LASSALLE, GILBERT、GREE, RENE
DOI:——
日期:——
Preparation of Oxepanes, Oxepenes, and Oxocanes by Iodoetherification using Bis(<i>sym</i>-collidine)iodine(I) Hexafluorophosphate as Electrophile
作者:Yves Brunel、Gérard Rousseau
DOI:10.1021/jo960506t
日期:1996.1.1
Oxepanes have been obtained in good yields (40-95%) by iodoetherification of unsaturated alcohols using bis(sym-collidine)iodine(I) hexafluorophosphate (1) as electrophile, either by 7-exo-mode or 7-endo-mode cyclizations. 4-Oxepenes could also be formed from 4,6-heptadien-1-ols; the presence of a substituent on the carbon 6 appeared necessary, while for steric reasons the presence of a substituent on the carbon 7 was unfavorable. Oxocanes could be obtained in moderate yields (18-27%).
Tetrahydrofuran, tetrahydropyran and oxepane formation by cobaloxime π-cation cyclizations
作者:Lana M. Grubb、Katherine A. Brown、Bruce P. Branchaud
DOI:10.1016/s0040-4039(98)00601-7
日期:1998.5
reported on the cyclization of (ω-hydroxy-β-hydroxyalkyl)cobaloximes (1, 2 and 3) to form 5, 6 and 7-membered ringcyclicethers (4, 5 and 6). Reversible cyclization and eventual irreversible alkene decomplexation (to form 7, 8 and 9) varied as a function of ring size. The practical consequence is that cyclizations to form 5 and 6 membered rings are feasible whereas formation of a 7 membered ring is not.