The regioselective reduction of one azido group in glycopyranoside and mannitol derivatives containing two azido functions with triphenylphosphine is described. In cyclic substrates with two secondary azides, equatorial azides were reduced in good yields in preference to axial azides. Steric, but not electronic, factors appear to determine the regiochemical outcome of the Staudinger reduction.
介绍了用
三苯基膦还原含有两个
叠氮功能的
吡喃糖苷和
甘露醇衍
生物中的一个
叠氮基团的区域选择性。在含有两个仲
叠氮基团的环状底物中,赤道
叠氮基团比轴向
叠氮基团更容易被还原。立体因素而非电子因素似乎决定了施陶丁格还原反应的区域
化学结果。