In the presence of a carboxyl group positioned for participation, NaBH(OAc)3 will reduce the usually unreactive ketones in a stereoselective manner. This reaction was applied in a key step to prepare precursors 7 and 15 toward the title compounds 1 and 2. These results are consistent with the exchange of one of the acetoxy groups in the reducing agent with the carboxy group followed by intramolecular
在存在参与定位的羧基的情况下,NaBH(OAc)3将以立体选择性方式还原通常不反应的酮。在关键步骤中应用该反应以制备朝向标题化合物1和2的前体7和15。这些结果与还原剂中的乙酰氧基之一与羧基的交换,随后
氢化物的分子内递送是一致的。