Treatment of ethyl α-(bromomethyl)acrylate with Cr(II) reagent derived from CrCl3 and LiAlH4 produces allylic chromium species which add to aldehydes efficiently to give α-methylene-γ-butyrolactones stereoselectively.
用来自 CrCl3 和 LiAlH4 的 Cr(II) 试剂处理 α-(
溴甲基)
丙烯酸乙酯会产生烯丙基
铬,这种
铬能与醛有效结合,立体选择性地生成 α-亚甲基-
γ-丁内酯。