HETEROCYCLES

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.

■ Site Selectivity in the 1,3-Dipolar Cycloaddition Reaction of Unsymmetric Pyridinium Bis(methoxycarbonyl)methylides with Methyl Propiolate

Kiyoshi Matsumoto,* Yukio Ikemi, Hideyuki Konishi, Xiao-lan Shi, and Takane Uchida

*Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-Nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan

Abstract

The 1,3-dipolar cycloaddition of.unsymmetric pyridinium bis(methoxycarbonyl)methylides with methyl propiolate proceeds in moderate to good yields with high to moderate site selectivity with respect to the ylide. Polar 3-substituted pyridinium bis(methoxycarbonyl)methlides generally gave predominantly the corresponding 8-substituted indolizines regardless of the substituents. The results can be explained by dipole-dipole interactions.