The cyclization of compounds obtained from ethyl dienol ether and dienyl pivalate derivatives of Hagemann's ester has been examined. The carbanions of methyl phenyl sulfone and methyl phenyl sulfoxide react with the methylated dienol ether (4) to give the β-keto sulfone (8) and sulfoxide (9), the former of which was converted into the oxabicyclo[4.3.0]non-1-en-3-one (16). The iodide (17) with potassium t-butoxide in t-butyl alcohol gave the octahydronaphthalenone (18). With lithium ethoxide in tetrahydrofuran the octahydronaphthalenedione (22) was obtained from the dienyl pivalate (24). Both reactions involve the generation and intramolecular cyclization of a dienolate produced by cleavage of the pivaloyl group in each of (17) and (24). The scope and limitations of these reactions are briefly discussed.
我们研究了由二烯醇
乙醚和
新戊酸二烯酯衍
生物哈格曼酯得到的化合物的环化过程。甲基苯基砜和
甲基苯基亚砜的碳离子与甲基化的二烯醇醚 (4) 反应,生成 β-酮基砜 (8) 和亚砜 (9),前者被转化成氧杂双环[4.3.0]
壬-1-烯-3-酮 (16)。
碘化物(17)与
叔丁醇中的
叔丁醇钾反应,得到八氢
萘酮(18)。在
四氢呋喃中加入
乙醇锂,从
新戊酸二烯酯(24)中得到八氢
萘醌(22)。这两个反应都涉及到(17)和(24)中的
新戊酰基裂解产生的二烯酸酯的生成和分子内环化。本文简要讨论了这些反应的范围和局限性。