Morita Masao, Sakaguchi Satoshi, Ishii Yasutaka
Department of Applied Chemistry, Faculty of Engineering & High Technology Research Center, Kansai University, Suita, Osaka 564-8680, Japan.
J Org Chem. 2006 Aug 4;71(16):6285-6. doi: 10.1021/jo060860j.
One-pot synthesis of gamma,delta-unsaturated carbonyl compounds from allyl alcohols and vinyl or isopropenyl acetates was achieved through in situ generation of allyl vinyl ethers by the action of the [IrCl(cod)]2 complex followed by Claisen rearrangement of the resulting ethers. For instance, the reaction of trans-2-methyl-3-phenyl-2-propen-1-ol with isopropenyl acetate in the presence of [IrCl(cod)]2 (1 mol %) and Cs2CO3 (5 mol %) at 100 degrees C for 3 h followed by 140 degrees C for 15 h afforded 5-methyl-4-phenyl-5-hexen-2-one in 72% yield. When vinyl acetate was employed in place of isopropenyl acetate, 4-methyl-3-phenyl-4-pentenal was obtained in 83% yield.
通过[IrCl(cod)]₂配合物作用原位生成烯丙基乙烯基醚，随后所得醚进行克莱森重排，实现了由烯丙醇与乙酸乙烯酯或乙酸异丙烯酯一锅法合成γ,δ-不饱和羰基化合物。例如，反式-2-甲基-3-苯基-2-丙烯-1-醇与乙酸异丙烯酯在[IrCl(cod)]₂（1 mol%）和碳酸铯（5 mol%）存在下，于100℃反应3小时，然后在140℃反应15小时，以72%的产率得到5-甲基-4-苯基-5-己烯-2-酮。当使用乙酸乙烯酯代替乙酸异丙烯酯时，以83%的产率得到4-甲基-3-苯基-4-戊烯醛。
