American Chemical Society (ACS) Acta Medica Okayama 0022-3263 86 14 2021 Toward the Synthesis of Paspaline-Type Indole-Terpenes: Stereoselective Construction of Core Scaffold with Contiguous Asymmetric Quaternary Carbon Centers 9802 9810 EN Ichiro Hayakawa Graduate School of Integrated Basic Sciences, Nihon University, 3-25-40 Sakurajosui, Setagaya-ku, Tokyo 156-8550, Japan Naochika Matsumaru Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan Akira Sakakura Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan The core scaffold of paspaline-type indole-terpenes was synthesized by using the House–Meinwald rearrangement as a key step. Rearrangement of the epoxide methyl group in the precursor with MABR (methylaluminum bis(4-bromo-2,6-di-tert-butylphenoxide)) as a Lewis acid proceeded smoothly to construct contiguous asymmetric quaternary carbon centers by a 1,2-chirality transfer. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry Acta Medica Okayama 1359-7345 55 27 2019 Catalytic enantioselective Hosomi-Sakurai reaction of ƒ¿-ketoesters promoted by chiral copper(ii) complexes 3923 3926 EN Yutaro Niwa Graduate School of Natural Science and Technology, Okayama University Mayu Miyake Graduate School of Natural Science and Technology, Okayama University Ichiro Hayakawa Graduate School of Natural Science and Technology, Okayama University Akira Sakakura Graduate School of Natural Science and Technology, Okayama University A catalytic enantioselective Hosomi–Sakurai reaction of ƒ¿-ketoesters has been developed. A copper(II) complex with a chiral bis(oxazoline) ligand bearing methanesulfonamide groups shows excellent catalytic activity to give ƒ¿,ƒ¿-disubstituted ƒ¿-hydroxyesters in high yields with high enantioselectivities. This is the first successful method for the catalytic enantioselective 1,2-addition of ƒ¿-ketoesters with allylic silanes. No potential conflict of interest relevant to this article was reported.