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.

■ Synthesis of Quinolizidinone and Indolizidinone Using N-Acyliminium Ion Cyclization and a One-Pot Procedure for Preparation of Benzoquinolizidinone

Punlop Kuntiyong,* Nuanpan Piboonsrinakara, Pijitra Bunrod, Duangkamol Namborisut, Sunisa Akkarasamiyo, Poramate Songthammawat, Chitlada Hemmara, Artid Buaphan, and Boonsong Kongkathip

*Department of Chemistry, Faculty of Science, Silpakorn University, 6 Rajamanka Nai Rd, Muang Nakhon Pathom 73000, Thailand

Abstract

Quinolizidinone, and indolizidinone systems were synthesized in a non-racemic form using cyclization of chiral N-acyliminium ions. The key reactive intermediates were prepared from the corresponding 2-arylethylamine or 3-butenylamine and L-glutamic acid or L-aspartic acid. The stereocenter bearing a dibenzylamino group was used for stereocontrol and resulted in diastereomeric products. A one-pot procedure for synthesis of benzoquinolizidinone was also developed. The dibenzylamino moiety was subsequently converted via Cope elimination to the corresponding cyclic enamide which is suitable as a synthetic precursor for a variety of quinolizidine alkaloids in enantiomerically pure form.