P-22 抗ストレス性潰瘍物質Al-77-Bおよびその関連物質の合成研究(ポスター発表の部)

概要

論文の詳細を見る
The AI-77-B (1), isolated from a culture broth of Bacillus pumilus AI-77 by Shimojima and co-workers, exhibits potent gastroprotective activity without antichlorinergic, antihistaminergic, or central suppressive effects. Prompted by its interesting biological activity and unique structure, six groups have reported the total synthesis of 1. In this symposium, we report a more efficient enantioselective total synthesis of 1 and 2. Right segment 5 was synthesized from known aldehyde 11 through Cordova's asymmetric epoxidation and TFA-mediated hydroxylactonization. Benzamide derivative 24 was subjected to coupling reaction with azidoepoxide 23 prepared via Sharpless asymmetric epoxidation to furnish 25. The coupling product 25 was converted into left segment 6 via lactonizaton and reduction. Condensation between 5 and 6 followed by deprotection afforded 2. Finally, hydrolysis of its five-membered lactone moiety gave 1. Thus, an efficient enantioselective total synthesis of 1 and 2 has been accomplished in 10 steps from 11.
2007-08-24