Novel formal synthesis of cephalotaxine via a facile Friedel-Crafts cyclization.
[structure: see text]. A novel formal synthesis of cephalotaxine (CET), the parent structure of the antileukemia Cephalotaxus alkaloids, was achieved via a facile Friedel-Crafts cyclization 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 skeletal isomerization of the CET core ring system (B, X = H2) were observed.
Li
Wei-Dong Z
WD
State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, China. wdli@nankai.edu.cn
Wang
Xin-Wei
XW
D000972:Antineoplastic Agents, Phytogenic / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D006248:Harringtonines / Q000138:chemical synthesis* / Q000737:chemistry; D000077863:Homoharringtonine; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013237:Stereoisomerism
D000972:Antineoplastic Agents, Phytogenic; D006248:Harringtonines; D000077863:Homoharringtonine