Synthesis of the Carbon Framework of Scholarisine A by Intramolecular Oxidative Coupling

Authors

  • Tsugunori Watanabe,

    1. Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1, Tanabe-dori, Mizuho-ku, Nagoya, 467-8603 (Japan), Fax: (+81) 52-836-3435
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  • Dr. Naoki Umezawa,

    1. Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1, Tanabe-dori, Mizuho-ku, Nagoya, 467-8603 (Japan), Fax: (+81) 52-836-3435
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  • Dr. Nobuki Kato,

    Corresponding author
    1. Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1, Tanabe-dori, Mizuho-ku, Nagoya, 467-8603 (Japan), Fax: (+81) 52-836-3435
    • Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1, Tanabe-dori, Mizuho-ku, Nagoya, 467-8603 (Japan), Fax: (+81) 52-836-3435

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  • Prof. Dr. Tsunehiko Higuchi

    Corresponding author
    1. Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1, Tanabe-dori, Mizuho-ku, Nagoya, 467-8603 (Japan), Fax: (+81) 52-836-3435
    • Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1, Tanabe-dori, Mizuho-ku, Nagoya, 467-8603 (Japan), Fax: (+81) 52-836-3435

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Abstract

Scholarisine A, isolated from the leaves of Alstonia scholaris, is a monoterpene indole alkaloid with an unprecedented cage-like structure. In this paper, preparation of the distinctive cage-like core skeleton of scholarisine A is described. The key feature of this synthetic strategy is an intramolecular oxidative coupling reaction at the late stage to construct a 10-oxa-tricyclo[5.3.1.03, 8]undecan-9-one structure fused with indolenine. Intramolecular oxidative coupling by using N-iodosuccinimide gave the carbon framework of scholarisine A in moderate yield, which is the first example of intramolecular oxidative-coupling reaction between non-activated enolate and indole. This study lays the foundation for continued investigations towards the total synthesis of scholarisine A.

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