Synthesis and ring-opening reaction of novel 1,3-dehydroadamantanes possessing phenyl and alkoxyl substituents

摘要: Abstract A series of novel 1,3-dehydroadamantanes (DHAs) possessing phenyl or alkoxyl substituents, such as 5-phenyl-1,3-dehydroadamantane, 5-butyl-7-phenyl-1,3-dehydroadamantane, 5-methoxy-1,3-dehydroadamantane, 5-butoxy-1,3-dehydroadamantane, 5-butyl-7-methoxy-1,3-dehydroadamantane, and 5-butoxy-7-butyl-1,3-dehydroadamantane were synthesized subjected to react with acidic compounds. 1,3-Dibromoadamantanes carrying substituents converted into the corresponding DHAs via intramolecular Wurtz-type coupling reactions lithium metal in THF 23–62% yields. Ring-opening readily occurred acetic acid methanol under conditions form various 1-acetoxyadamantanes 1-methoxyadamantanes containing groups. The resulting 1-butyl-3-methoxy-5-phenyladamantane, 1-acetoxy-3-butyl-5-phenyladamantane, 1-acetoxy-3-butyl-5-methoxyadamantane, 1-acetoxy-3-butoxy-5-butyladamantane, 1-butoxy-3-butyl-5-methoxyadamantane possessed stereogenic center. high reactivity inverted 1,3-carbon–carbon σ-bond toward compounds indicated electron density, which was supported by sp2 character cyclopropane rings estimated JC–H constants 13C NMR analyzes.