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:

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

Paper | Regular issue | Vol 63, No. 3, 2004, pp.539-565
Published online, 9th January, 2004
DOI: 10.3987/COM-03-9952
Synthetic Studies on Azaspiracid, a Novel Shellfish Poison: Attempts to Construct the ABCD Ring System

Yuichi Ishikawa and Shigeru Nishiyama*

*Department of Chemistry, Faculty of Science and Technology, Keio University, Hiyoshi 3-14-1, Kohoku-ku, Yokohama 223-8522, Japan


Synthesis of the ABCD ring system of azaspiracid (1) was attempted. Construction of the highly substituted tetrahydrofuran (9) via the Pd(0)-mediated cyclization, followed by spirocyclization afforded trispiro-ring (28), carrying an unnatural ring-junctions. The BCD ring system of 1 was successfully produced by using the bridge of a sulfur atom between the B and C ring to control the spiroacetal center of the C13 position. The stereostructures were unambiguously determined by the NOE experiments.