Optically active cerulenin 1, a potent inhibitor of fatty acid synthetase, was prepared via the condensation of the epoxy aldehyde 8 and the alkenyl lithium 16. In order to evaluate the effects of (E, E)-1, 4-double bounds of the cerulenin side chain on the interaction with the enzyme, a series of optically active cerulenin analogs 32a-i with modified side chains and tetrahydrocerulenin 3 were synthesized by similar procedures.
11-Chloro-3-methoxy-2-undecenal was synthesized from 8-bromooctanol, and an annelation reaction with this aldehyde and ethyl acetoacetate proceeded to give the ethyl 6-(8-chlorooctyl)salicylate. Ethyl 6-(8-chlorooctyl)salicylate was converted to ethyl 6-(7-formylheptyl)-2-methoxybenzoate through the iodide after protection of the phenolic hydroxyl group. Finally, the Wittig reaction with the aldehyde and triphenylphosphonium
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%).