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: ¥ 4,320 (Yen only)
Period: This Article can be accessed for 7 days.

Communication | Regular issue | Vol 85, No. 12, 2012, pp.2927-2932
Published online, 25th October, 2012
DOI: 10.3987/COM-12-12599
Synthesis of (±)-Esermethole via an Intramolecular Carbamoylketene-Alkene [2+2] Cycloaddition

Tsukasa Ozawa, Makoto Kanematsu, Hiromasa Yokoe, Masahiro Yoshida, and Kozo Shishido*

*Graduate School of Pharmaceutical Sciences, University of Tokushima, 1-78-1 Sho-machi, Tokushima 770-8505, Japan

Abstract

A synthesis of (±)-esermethole (2), a synthetic precursor of physostigmine (1), has been accomplished by using an intramolecular carbamoylketene-alkene [2+2] cycloaddition followed by nitrone-mediated regioselective ring expansion for the construction of the basic carbon framework of 2 as the key steps.