(1E,3Z)-1-Aryl-4-methanesulfonyl-2-nitro-1,3-butadienes (8), derived from the initial ring-opening of 3-nitrothiophene (5), have been found to undergo a facile base-induced cyclization leading to thiopyran S,S-dioxides (9), thus furnishing a further example of effective ring-enlargement from 5- to 6-membered sulfur heterocycles. Compounds 9 are obtained as single racemic mixtures in satisfactory yields: they still contain a nitrovinylic moiety, which can be exploited for further modifications targeted to new derivatives endowed with either synthetic or pharmacological potentialities e.g., in the field of L-type Ca2+-channel blockers. (C) 2008 Elsevier Ltd. All rights reserved.
从
3-硝基噻吩(5)的初始开环反应中得到的(1E,3Z)-1-芳基-4-甲磺酰基-2-硝基-
1,3-丁二烯(8),已被发现会在碱性条件下发生简便的环化反应,生成噻二
吡喃S,S-二
氧化物(9),从而为由5元
硫杂环扩大为6元
硫杂环提供了一个有效的范例。化合物9以单一外消旋混合物的形式获得,且收率满意:它们仍然含有一个
硝基乙烯基部分,可进一步进行修饰以制备具有合成或药理学潜力的新衍
生物,如在L型
钙离子通道阻滞剂领域中的应用。© 2008 Elsevier Ltd. 保留所有权利。