Investigations on the essential conformation of adrenergic catecholamines led us to synthesize 6-amino-1, 2-dihydroxy-6, 7, 8, 9-tetrahydro-5H-benzocyclohepten-5-ol derivatives (1), which are seven-membered rigid analogues of catecholamines. Although catalytic reduction of the amino ketones (9 and 10) leading to the analogues of noradrenaline and isoproterenol (1a and 1c) yielded mixtures of 5, 6-cis and trans isomers, it was found that lithium aluminum hydride reduction of α-hydroxyimino ketone (12) gave exclusively cis-amino alcohol (13a-cis) and that reduction of α-acetamido ketone (14) with sodium borohydride followed by hydrolysis afforded 13a-trans. Several pairs of 5, 6-cis and trans isomers of 1 were prepared by catalytic reduction of 13a-cis and 13a-trans or their Nsubstituted derivatives. N-tert-Butyl derivative (1d-trans) was prepared via 13d-trans which was obtained by hydrolysis of an azirizino compound (24).
对
肾上腺素能
儿茶酚胺基本构象的研究促使我们合成6-
氨基-
1,2-二羟基-6,7,8,9-四氢-5H-苯并
环庚酮-5-醇衍
生物(1)结构式,这是
儿茶酚胺的七元环刚性类似物。通过催化还原
氨基酮(9和10)而得到
去甲肾上腺素和
异丙肾上腺素类似物(1a和1c),产物为5,6-顺式和反式的混合物。但后来发现,用
氢化铝锂还原α-羟基
亚胺酮(12)可以得到唯一的顺式
氨基醇(13a-顺式),而用
硼氢化钠还原α-乙酰胺酮(14),再经
水解得到13a-反式。通过催化还原13a-顺式和13a-反式及其N取代衍
生物,合成了多对5, 6-顺式和反式异构体1。N-叔丁基衍
生物(1d-反式)通过13d-反式得到,后者是通过
水解氮杂
环丁烷化合物(24)获得的。