Stereoselective Synthesis of Medium-Sized Cyclic Compounds by Means of Tandem Reactions of a Cyclic Oxosulfonium Ylide with Acetates of Baylis−Hillman Adducts
作者:Hitoshi Akiyama、Tetsuya Fujimoto、Katsuyoshi Ohshima、Kenji Hoshino、Yuko Saito、Ayu Okamoto、Iwao Yamamoto、Akikazu Kakehi、Ryozo Iriye
DOI:10.1002/1099-0690(200106)2001:12<2265::aid-ejoc2265>3.0.co;2-8
日期:2001.6
five-membered cyclic oxosulfonium ylide 3 with β-acetoxy-α-methylene ketones in the presence of two equimolar amounts of base afforded the cycloheptene oxide derivatives 7a−i as single stereoisomers in 19−77% yields. The products were considered to form through a Michael-type addition of the ylide, followed by elimination of the acetoxy group and an intramolecular Corey−Chaykovsky reaction. On the
在两种等摩尔量的碱存在下,用 β-乙酰氧基-α-亚甲基酮处理五元环状氧锍叶立德 3 得到环庚烯氧化物衍生物 7a-i 作为单一立体异构体,产率为 19-77%。产物被认为是通过叶立德的迈克尔型加成形成的,然后是乙酰氧基的消除和分子内的 Corey-Chaykovsky 反应。另一方面,相同的处理,当使用六元氧锍叶立德时,以中等产率得到相应的环辛烯氧化物衍生物,产物在大约 10 分钟内形成。4:1 的立体异构体混合物,这一事实与亚磺酰基中硫原子构型的差异有关。