Studies on quinones. XII. Cycloketalization of michael adducts from hydroxyquinones
作者:Raúl Cassis、Ricardo Tapia、Jaime A. Valderrama
DOI:10.1002/jhet.5570210345
日期:1984.5
ammonium chloride resulted in the formation of the p-quinonic cycloketals: trans- and cis-4-phenyl-2-methyl-2-methoxy-3,4-dihydro-2H-naphtho[2,3-b]pyran-5,10-dione (2a,2b). Cyclization of the Michael adducts 6, 10 and 11, which are structurally related to 1, with trimethyl orthoformate-methanol-ammonium chloride gave the corresponding p-quinonic cycloketals 7, 12 and 13. The structures of the regioisomers
2-羟基-3-(1-苯基-3-氧丁基)-1,4-萘醌(1)与酸性甲醇或原甲酸三甲酯,甲醇和氯化铵的混合物的反应导致生成对-醌cycloketals:反式-和顺式-4-苯基-2-甲基-2-甲氧基-3,4-二氢-2 ħ -萘并[2,3- b ]吡喃-5,10-二酮(2A,2B)。迈克尔加合物环化6,10和11,其在结构上与1,与氯化原甲酸三甲酯-甲醇-铵,得到相应的p -quinonic cycloketals 7,12和13。基于化合物7的光谱性质并通过分析其质子核磁共振谱,提出了区域异构体2a和2b的结构。