Beilstein J. Org. Chem.2014,10, 2421–2427, doi:10.3762/bjoc.10.252
Takayuki Tonoi Keisuke Mameda Moe Fujishiro Yutaka Yoshinaga Isamu Shiina Department of Applied Chemistry, Tokyo University of Science,1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan 10.3762/bjoc.10.252 Abstract The first total synthesis of the proposed structure of astakolactin, a
sesterterpene metabolite isolated from the marine sponge Cacospongia scalaris, has been achieved, mainly featuring Johnson–Claisen rearrangement, asymmetric Mukaiyama aldol reaction and MNBA-mediated lactonization.
Keywords: aldol reaction; astakolactin; lactonization; MNBA; terpenoids; Introduction
Astakolactin (1) is a novel sesterterpene metabolite [1][2][3][4][5] first reported in 2003 by Roussis et al [6]. It was isolated from the marine sponge Cacospongia scalaris, which was collected from the gulf of Astakos in the Ionian Sea near Greece. The structure proposed for compound 1 is a bicyclic linear