A convenient access to (3S)-3-(triisopropylsilyl)oxy-1-pyrroline N-oxide, a useful intermediate for polyfunctionalized enantiopure indolizidine and pyrrolizidine synthesis
作者:Andrea Goti、Martina Cacciarini、Francesca Cardona、Alberto Brandi
DOI:10.1016/s0040-4039(99)00310-x
日期:1999.4
steps and 28% overall yield from l-malic acid has been achieved by the combined use of DIBAL-H as the reductant and triisopropylsilyl as the protecting group. The utility of nitrone 2 as synthetic intermediate is demonstrated by a ready access to polyhydroxylated indolizidines and pyrrolizidines via stereoselective 1,3-dipolar cycloaddition reactions.
通过组合使用DIBAL-H作为还原剂和三异丙基甲硅烷基作为保护基团,可以优化五步提供对映体纯的硝酮2以及从l-苹果酸中获得28%的总收率的策略。通过立构选择性的1,3-偶极环加成反应可容易地获得多羟基化的吲哚并立兹和吡咯并立兹,证明了硝酮2作为合成中间体的用途。