γ-丁内酯α-烷基化的新方法

采用两步简单反应，顺利地得到α－取代的γ－丁内酯。首先，在醇钠存在下，严格控制反应温度为0－10℃，以内酯与芳香醛类化合物，选择性地缩合为α－烯基内酯（1a-1i）产率40％－99％，进而采用催化转移氢化的方法，在Pd/C存在下，用NaH2PO2氢化还原上述缩合中间物，使有效地转化为α－烷基化γ－丁内酯，产率55％－99％（2a-2e）。该方法能有效地得到目标化合物，具有方法简单易行，操作方便，反应条件温和，试剂价廉和产率相对较高的特点。

A New Method for α-Alkylation of γ-Butyrolactone

The α-alkylation products of γ-butyrolactone can be gained via two simple and convenient steps:(E)-α-Alkenyl-γ-butyrolactone comp ounds were synthesized from condensation of corresponding aromatic aldehydes and γ-butyrolactone,using common base such as MeONa and EtONa.Then the (E) -α-Alkenyl-γ-butyrolactones were reduced to α-alkyl-γ-bu tyrolactones by using sodium hypophosphite with Pd/C catalyst,which is named to be reaction of catalytic transfer hydrogenation.