Synthesis of (-)-Trolline, (-)-Crispine A and (-)-Crispine E

Abstract

Biologically active 1-subsutituted tetrahydroisoquinoline alkaloids, (-)-trolline, (-)-crispine A, and (-)-crispine E were synthesized using a chiral isoquinolinecarbaldehyde as a key material.The aldehyde was readily obtained from a 1-cyanoisoquinoline, and subjected to a Horner-Wadsworth-Emmons reaction.The chiral tetrahydroisoquinoline derivative thus obtained was used for the synthesis of the optically active isoquinoline alkaloids.