title: Synthesis and Resolution of Substituted [5]Carbohelicenes.
abstract: Three types of racemic [5]helicenyl acetates (1a, 2, and 3a) were synthesized. The synthesis of 2 was achieved by regioselective oxidation using o-iodoxybenzoic acid. The enzymatic kinetic resolution of 1a-3a was studied. The conversion with the highest rate and ee was obtained using 1a as the substrate and lipase Amano PS-IM as the enzyme. The two enantiomers of 1-[5]helicenol 3b were separated using (1S)-10-camphorsulfonyl chloride as the chiral resolving agent.
authors.affiliation: †Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Kazuteru
authors.initials: K
authors.lastname: Usui
authors.affiliation: †Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: †Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Shimizu
authors.affiliation: †Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Mieko
authors.initials: M
authors.lastname: Okazumi
authors.affiliation: †Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Biao
authors.initials: B
authors.lastname: Mei
authors.affiliation: ‡Japan and Division of Organic Chemistry, National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya, Tokyo 158-8501, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Demizu
authors.affiliation: ‡Japan and Division of Organic Chemistry, National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya, Tokyo 158-8501, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kurihara
authors.affiliation: †Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suemune