A Friedel-Crafts cyclization approach toward cephalotaxine
摘要:
The 1-azaspiro[4.4]nonane portion 11 of cephalotaxine was prepared via an intramolecular S(N)2' substitution reaction followed by ozonolysis; condensation of 11 with the aromatic portion 13 gave compound 15; a Friedel-Crafts cyclization of 15 in polyphosphoric acid smoothly afforded the cephalotaxine skeleton 16. A single-crystal X-ray analysis of the HCl salt of 16 confirmed the structure of 16.
Transannular Reactions of Peptides. The Peptide Nitrogen in a 10-Membered Ring<sup>1,2</sup>
作者:Louis A. Cohen、Bernhard Witkop
DOI:10.1021/ja01629a050
日期:1955.12
Intramolecular 1,3-dipolar cycloaddition of alkyl azide enones and rearrangements of the triazoline intermediates. Formal total synthesis of (.+-.)-desamylperhydrohistrionicotoxin
作者:Chin Kang Sha、Sheng Lian Ouyang、Der Yung Hsieh、Ruei Chih Chang、Shang Chia Chang
DOI:10.1021/jo00359a019
日期:1986.5
SHA, CHIN-KANG;YOUNG, JENN-JONG;YEH, CHUN-PONG;CHANG, SHANG-CHIA;WANG, SU+, J. ORG. CHEM., 56,(1991) N, C. 2694-2696