Novel Formal Synthesis of Cephalotaxine via a Facile Friedel−Crafts Cyclization
作者:Wei-Dong Z. Li、Xin-Wei Wang
DOI:10.1021/ol070024b
日期:2007.3.1
[structure: see text]. A novel formal synthesis of cephalotaxine (CET), the parent structure of the antileukemia Cephalotaxus alkaloids, was achieved via a facile Friedel-Craftscyclization of the amino (or amido) spiro-cyclopentenone precursor (A) mediated by a protic acid leading to tetracyclic ketone B. A remarkable stereoelectronic effect of the methylenedioxy substituent (R) and an interesting