Norbornadiene-Fused Heterocycles: Synthesis of 5,8-Dihydro-5,8-methanophthalazines and Regioselective Ring Cleavage and Skeletal Rearrangement of 6,7-Epoxy-5,6,7,8-tetrahydro-5,8-methanophthalazine 2-Oxides in Trifluoroacetic Acid
作者:Tomoshige Kobayashi、Hideki Sugawara、Behrooz Nikaeen
DOI:10.1246/bcsj.71.497
日期:1998.2
5,8-Dihydro-5,8-methanophthalazine, prepared by the reaction of bicyclo[2.2.1]hepta-2,5-diene-2,3-dicarbaldehyde with hydrazine, reacted with MCPBA to give an N-oxide. Further oxidation with MCPBA afforded the corresponding exo-6,7-epoxy derivative. Treatments of the epoxide and its diphenyl-substituted derivative with trifluoroacetic acid gave 6,9-bis(trifluoroacetoxy) derivatives by a regioselective
5,8-Dihydro-5,8-methanophthalazine,由双环[2.2.1]庚-2,5-二烯-2,3-二甲醛与肼反应制备,与MCPBA反应生成N-氧化物。用 MCPBA 进一步氧化得到相应的 exo-6,7-环氧衍生物。用三氟乙酸处理环氧化物及其二苯基取代的衍生物,通过环氧乙烷的区域选择性开环,伴随着 Wagner-Meerwein 重排得到 6,9-双(三氟乙酰氧基)衍生物。双(三氟乙酰氧基)衍生物被转化为相应的二醇以阐明它们的区域和立体化学。