22 フッ化セシウム存在下でのアリールプロパルギルエーテルのクライゼン転位 : 2-メチルアリールフランの生成とそのイソキノリンアルカロイド合成への応用(ポスター発表の部)

DOI

書誌事項

タイトル別名
  • 22 Cesium Fluoride-Mediated Claisen Rearrangement of Aryl Propargyl Ether : Formation of 2-Methylarylfuran and its Application to Syntheses of Some Isoquinoline Alkaloids

抄録

Thermal Claisen rearrangement of an aryl propargyl ether has been recognized as a general method for the preparation of arylpyrans. In the course of synthetic studies on benzo[c]phenanthridine alkaloids we occasionally found that isomeric 2-methylarylfurans, instead of desired arylpyrans, were formed in excellent yield when the ethers were subjected to the rearrangement in the presence of cesium fluoride (CsF). The precise examination of the CsF-mediated Claisen rearrangement using 2-naphthyl propargyl ether (3) is described. Satisfactory transformation of the 2-methylarylfuran to the salicylaldehyde derivative was achieved by stepwise oxidation using osmium tetroxide and sodium periodate. Combination of the CsF-mediated Claisen rearrangement and the oxidation serves as a useful method for regioselective introduction of a C_1 unit to ortho position of phenol group. Chelerythrine (1) (II: R=Me) has four sequentially substituted benzene ring (ring A) in its molecule. Application of this strategy to the phenol amide (12) led to total synthsis of 1, which could be prepared from the 2-methylbenzofuran (20) derived through the CsF-mediated Claisen rearrangement of isovanillin (17). The furan (20) was also available to synthesis of lemaireocereine (2) belonging to simple isoquinoline alkaloid. Thus the furan ring in 2-methylfuran can act as not only a source of C_1 unit but also a protecting group for phenol, in other words as a masked salicylaldehyde.

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詳細情報 詳細情報について

  • CRID
    1390001206079783168
  • NII論文ID
    110006678990
  • DOI
    10.24496/tennenyuki.33.0_164
  • ISSN
    24331856
  • 本文言語コード
    ja
  • データソース種別
    • JaLC
    • CiNii Articles
  • 抄録ライセンスフラグ
    使用不可

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