Simple and Practical Routes to 4,5-Benzocycloheptenone. Ring Enlargement of 3,4-Dihydro-2-ethoxynaphthalene and 2-Alkoxynaphthalenes with Dichlorocarbene
作者:Tadao Uyehara、Akio Ichida、Makoto Funamizu、Hirofumi Nanbu、Yoshio Kitahara
DOI:10.1246/bcsj.52.273
日期:1979.1
An addition of dichlorocarbene generated by a phase-transfer reaction, to 3,4-dihydro-2-ethoxynaphthalene gave 7,7-dichloro-6-ethoxy-2,3-benzobicyclo[4.1.0]hept-2-ene, from which 4,5-benzocycloheptenone was derived in preparative yield. 2-Methoxy- and 2-ethoxynaphthalene were converted into 2-chloro-4,5-benzotropone in 33 and 66% yield, respectively, by treatment with large excess of ethyl trichloroacetate arid sodium methoxide.
将通过相转移反应生成的二氯甲烷加到 3,4-二氢-2-乙氧基萘中,得到 7,7-二氯-6-乙氧基-2,3-苯并双环[4.1.0]庚-2-烯,并由此制备得到 4,5-苯并环庚烯酮。用大量过量的三氯乙酸乙酯和甲醇钠处理 2-甲氧基萘和 2-乙氧基萘,分别以 33% 和 66% 的收率转化为 2-氯-4,5-苯并托品酮。