| Research Abstract |
We recently developed the method for construction of asymmetric quarternary carbon center using stereoselective domino reactions, and now we have applied our method to asymmetric synthesis of biologically active pyrrolo[2,3-b]indoles, pseudophyrinaminol, flustramines, amauromin, and physostigumin derivatives. As its further application to construction of tertiary alcohol, we have approached to 3a-hydroxypyrrolo[2,3-b]indoles, flustraminol and alline.
1.The tandem olefination, isomerization and Claisen rearrangement of 2-allyloxyindolin-3-ones, derived from optically active allyl alcohols, proceeded high-stereoselectively to give optically active 3,3-disubstituted oxindoles, which were reduced to give optically active 3a-allylpyrrolo[2,3-b]indoles. We have accomplished efficiently asymmetric total synthesis of pseudophyrinaminol and flustramines A and B.
2.Olefination of 2-allylindolin-3-ones with optically active ylides, followed by isomerization to proceed asymmetric Claisen rearrangement to afford the optically active oxindoles in high yields. We have succeeded in total synthesis of unnatural pseudophyrinaminol.
3.We have achieved synthesis of 3a-allylphenserin as physostigumin derivative having the bulky moiety at 3a position..
4.We have established the synthetic method for 3-hydroxyoxindoles utilizing enolization-Claisen rearrangement of 2-allyloxyindolin-3-ones, and we have achieved total synthesis of donaxiridine, alline, and comvolutamydines A and B.
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