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3 data found. 1 - 3 listed

Published online: 26th March, 2015

Paper | Regular issue | Prepress
DOI: 10.3987/COM-15-13172
Divergent Synthesis of 2,6-Disubstituted Piperidine Alkaloid, (+)-Spectaline by Palladium-Catalyzed Cyclization

Masatomo Katsuyama, Masahiro Furuta, Kazuya Kobayashi, Kenta Teruya, Hidefumi Makabe, Kenichi Akaji, and Yasunao Hattori*

*Department of Medicinal Chemistry, Pharmacetuical Chemistry, Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Kyoto 607-8412, Japan

Abstract

Convergent synthesis of 2,6-disubstituted piperidine alkaloid, (+)-spectaline is described. Using substrate-controlled diastereo-selective Pd(II)-catalyzed cyclization, both cis-2,6- and trans-2,6-disubstituted piperidine backbones were constructed from adequately protected precursors with high selectivity. Synthesis of (+)-spectaline containing cis-2,6-disubstituents was accomplished by 10 step reactions with a 31% total yield.

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Published online: 26th March, 2015

Short Paper | Regular issue | Prepress
DOI: 10.3987/COM-15-13178
Four New Penicitrinols and Two New Penicillenols from the Marine-Derived Fungus Penicillium Citrinum

Li Chen,* Tong Zhou, Yan-Yan Zhao, Mei-Wei Gong, Qi-Wen Xia, Min-Gang Ying, Qiu-Hong Zheng, Qin-Ying Liu, and Qi-Qing Zhang*

*Institute of Biomedical and Pharmaceutical Technology , Fuzhou University, Fuzhou, 350002, P. R. China

Abstract

Six new compounds, penicitrinols L–O (14), penicillenols D1 (9) and D2 (10), together with six known compounds were isolated from the marine- -derived fungus Penicillium citrinum. Their structures were elucidated on the basis of comprehensive spectral analysis and chemical methods. All the new compounds were evaluated for their cytotoxic effects on the A-549, HL-60 and SW-620 cell lines by the MTT method. Penicitrinols L (1) and M (2) showed weak cytotoxicities against SW-620 cell line, while penicillenols D1 (9) and D2 (10) showed weak cytotoxicities against A-549 and HL-60 cell lines, respectively.

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Published online: 24th February, 2015

Review | Regular issue | Prepress
DOI: 10.3987/REV-15-818
Transition Metal-Catalyzed Intramolecular Cyclization of Propargyl Alcohols and Their Derivatives for the Synthesis of Highly Substituted Five-Membered Oxygen Heterocycles

Masahiro Egi* and Shuji Akai*

*Synthetic Medicinal Chemistry, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan

Abstract

The transition metal-catalyzed intramolecular cyclization of propargyl alcohols and their derivatives has been widely utilized in the synthesis of five-membered oxygen heterocycles such as furans, hydrofurans, and furanones. Prerequisites for the efficient transformations into highly substituted target compounds include the regioselectivity of the cyclization step and the chemoselectivity of the transition metal-mediated activation of substrates. This review documents recent progress on the title reactions by categorizing the initial activation modes of substrates.

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3 data found. 1 - 3 listed