Online article for Non-subscribers

Pay per view

Heterocycles has a pay-per-view service for Non-subscribers.
You will be able to directly purchase the full text article through PayPal.
Your purchased Paper can be downloaded after the payment is completed.
An e-mail will be sent the URL to download the paper.
If you have any questions, please contact: purchase@heterocycles.com

Price: ¥ 4,400 (Yen only)
Period: This Article can be accessed for 7 days.

Paper | Special issue | Vol 97, No. 1, 2018, pp.292-305
Published online, 2nd February, 2018
DOI: 10.3987/COM-18-S(T)19
Total Synthesis of Phenanthroquinolizidine Alkaloid Cryptopleurine and Phenanthroindolizidine Alkaloid Tylophorine

Yousuke Yamaoka,* Marie Taniguchi, Ken-ichi Yamada, and Kiyosei Takasu*

*Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-shimoadachi-machi, Sakyo-ku, Kyoto 606-8501, Japan

Abstract

Total synthesis of phenanthroquinolizidine alkaloid cryptopleurine was achieved in 11 steps from commercially available 6-bromoveratraldehyde. The crucial step of phenanthrene construction is a formal [2 + 2] cycloaddition of 2-acyl-2’-vinyl-1,1'-biaryl, followed by an acid promoted ring-contraction/ring-opening sequence. The key point to complete the total synthesis of cryptopleurine is use of nosyl amide as a nucleophile for cyclization of piperidine ring. The synthesis of tylophorine was also achieved in the similar manner.