Stereoselective preparation of methylenecyclobutane-fused angular tetracyclic spiroindolines via photosensitized intramolecular [2+2] cycloaddition with allene

TETRAHEDRON LETTERS

卷:60

Article

Arai, Noriyoshi¹  Ohkuma, Takeshi^1,2 

[1] Hokkaido Univ, Fac Engn, Div Appl Chem, Sapporo, Hokkaido 0608628, Japan

[2] Hokkaido Univ, Fac Engn, Frontier Chem Ctr, Sapporo, Hokkaido 0608628, Japan

关键词: Indole;    Allene;    Photoreaction;    [2+2] Cycloaddition;   

DOI  :  10.1016/j.tetlet.2019.151252

来源: Elsevier

【 摘 要 】

Irradiation of 3-(hexa-4,5-dienyl)indole derivatives in the presence of 3',4'-dimethoxyacetophenone by a high-pressure mercury lamp through Pyrex glass gave the corresponding [2+2] cycloaddition products stereoselectively in high yields. The major product was a methylenecyclobutane-fused angular tetracyclic spiroindoline derivative produced by the [2+2] cycloaddition through a parallel orientation. The minor product was a hexahydromethanocarbazole derivative through a crossed orientation. Electron-withdrawing substituents, such as acyl or alkoxycarbonyl, on the indole nitrogen were suitable for this reaction. (C) 2019 Elsevier Ltd. All rights reserved.

【 授权许可】

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