Synthesis of Dihydrobenzofuran Derivatives from Substituted<i>p</i>-Benzoquinones
作者:Tadashi Kozuka
DOI:10.1246/bcsj.55.2415
日期:1982.8
A series of p-benzoquinones having an ester functional group in the α position of alkyl side chains was prepared. Irradiation of these quinones, except for methyl 3-methyl-2-(4-methyl-3,6-dioxo-1,4-cyclohexadienyl)-butyrate (3e), rapidly gave methyl 3-substituted 2,3-dihydro-5-hydroxybenzofuran-2-carboxylate in fairly good yields, and it was found that rearrangement of the side chain occurred concomitantly
制备了一系列在烷基侧链的α位具有酯官能团的对苯醌。这些醌的辐照,除了甲基 3-甲基-2-(4-甲基-3,6-二氧代-1,4-环己二烯基)-丁酸 (3e) 外,迅速得到甲基 3-取代的 2,3-二氢-5 -羟基苯并呋喃-2-羧酸酯的产率相当好,并且发现侧链的重排伴随发生。醌 3e 的光解得到 2-(2,5-二羟基-4-甲基苯基)-3-甲基-3-丁烯酸甲酯作为主要产物。假定中间体可以解释孤立的光产物。
Intramolecular Ring-Opening Reactions of 1-(2-Methoxyphenyl)-6-oxabicyclo[3.2.0]heptanes: Spirocyclic Dihydrobenzofurans from Fused Bicyclic Oxetanes
Treatment of fused oxetanes with Et 2 AlCl, TMSCl, acetyl chloride, or ethereal hydrochloric acid leads to the formation of spirocyclic dihydrobenzofurans through intramolecular attack of an oxygen atom of a proximal phenolic methyl ether.
用 Et 2 AlCl、TMSCl、乙酰氯或醚性盐酸处理稠合氧杂环丁烷会导致通过分子内攻击近端酚类甲基醚的氧原子形成螺环二氢苯并呋喃。