One-Pot Synthesis of Tetrahydrofuran Derivatives from Allylic Alcohols and Vinyl Ethers by Means of Palladium(II) Acetate
作者:Keigo Fugami、Koichiro Oshima、Kiitiro Utimoto
DOI:10.1246/bcsj.62.2050
日期:1989.6
Reaction of allylicalcohol with vinyl ether in the presence of Pd(OAc)2 afforded furanderivatives in good yield. Pd(OAc)2 was essential for the reaction. PdCl2 complex did not afford cyclized product but gave acetal exclusively. Three components were combined at once to produce 4-(3-butenyl)-2-butoxy-4-methyltetrahydrofuran upon treatment of a mixture of 2-methyl-2-propen-1-ol, butyl vinyl ether
Intramolecular Radical Cyclization of 2-Haloethanal Allyl Acetal and Allyl 2-Halophenyl Ether with a Grignard Reagent in the Presence of Iron(II) Chloride
New Method for the Preparation of an Active Manganese Species and its Use for Radical Cyclization Reactions
作者:Jun Tang、Hiroshi Shinokubo、Koichiro Oshima
DOI:10.1055/s-1998-1897
日期:1998.10
Reduction of Li2MnCl4 with magnesium in THF afforded a fairly active manganese species which readily initiated radical cyclization of 2-iodoethanal allylic acetals at room temperature. The corresponding 2-bromoethanal acetals also provided the same cyclized products upon treatment with the activated manganese reagent at reflux in THF.
[GRAPHICS]Treatment of allyl beta-iodoacetals with ethylmagnesium bromide in THF provided tetrahydrofuran derivatives in good yields. On the other hand, the reaction in DME provided tetrahydrofuranylmethylmagnesium compounds in good yields.