Reductive cyclization of α-(2-hydroxyethyl)-β-methoxy-o-nitrocinnamic acid γ-lactone (4) with triethyl phosphite produced 3,4-dihydro-5-methoxy[1,3]oxazino[3,4-a]indol-1-one (6), a new heterocyclic ring system. Reduction of 2-o-nitrobenzoyl-γ-butyrolactone (3) yielded 4,5-dihydro-1′H-spiro[furan-3,2′-indole]-2,3′-dione (8) as the major product, in addition to a trace amount of the 5-ethoxy-analogue
亚磷酸三乙酯对α-(2-羟乙基)-β-甲氧基-邻硝基
肉桂酸γ-内酯(4)的还原环化反应生成3,4-二氢-5-甲氧基[1,3]恶嗪[3,4- a ] indol-1-one(6),一种新的杂环系统。还原2-邻
硝基苯甲酰基-
γ-丁内酯(3),得到4,5-二氢-1'H-螺[
呋喃-3,2'-
吲哚] -2,3'-二酮(8)为主要产物,以及痕量的(6)的5-乙氧基类似物。将内酯(8)
水解并脱羧,得到1,2-二氢-2-(2-羟乙基)
吲哚-3-酮(9)。这些结果提供了通往新型反应性杂环内酯的途径。