Methyl 2-(4′-hydroxybutyl)chromone-3-carboxylate (7) and the derived epoxide (13) undergo spirocyclisation on treatment with iodomethane–potassium carbonate and Lewis acid respectively.
CREMINS P. J.; WALLACE T. W., J. CHEM. SOC. CHEM. COMMUN.,(1986) N 21, 1602-1603
作者:CREMINS P. J.、 WALLACE T. W.
DOI:——
日期:——
Preparative routes to spiroacetals derived from chroman-4-one (2,3-dihydro-4H-1-benzopyran-4-one)
作者:Peter J. Cremins、Roy Hayes、Timothy W. Wallace
DOI:10.1016/s0040-4020(01)89903-8
日期:1993.4
Methyl 2-(4-hydroxybutyl)-4-oxo-4H-1-benzopyran-3-carboxylate 6 is transformed into the spiroacetals 13 and 14 (ratio 5:1) via treatment with iodomethane/potassium carbonate, the process involving sequential intramolecular conjugate addition and enolate alkylation. The 2,3-epoxide 7 derivedfrom 6 undergoes spirocyclisation to the hydroxyesters 16 and 17 upon treatment with acids. The structures of
通过碘甲烷/碳酸钾处理,将2-(4-羟丁基)-4-氧代-4 H -1-苯并吡喃-3-羧酸甲酯6转化为螺缩醛13和14(比例为5:1)。分子内共轭物加成和烯醇化烷基化。由6衍生的2,3-环氧化物7在用酸处理后经历螺环化成羟基酯16和17。X射线晶体学证实了13和16的结构。