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.
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.
A Friedel-Crafts cyclization approach toward cephalotaxine
作者:Chin Kang Sha、Jenn Jong Young、Chun Pong Yeh、Shang Chia Chang、Sue Lein Wang
DOI:10.1021/jo00008a023
日期:1991.4
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.