Synthesis of 7-azabicyclo[2.2.1]heptane derivatives by transformation of tropinone
作者:Elena Gómez-Sénchez、José Marco-Contelles
DOI:10.1002/jhet.5570430607
日期:2006.11
N-carbethoxytropinone (4), readily available from tropinone (3), affords mixtures of exo- and endo-isomers of 2,7-dicarbethoxy-7-azabicyclo[2.2.1]heptane (1b) in variable and moderate chemical yield (maximum 37%). The bromination (Br2, HBr/AcOH) reaction of compound 4 gives ethyl trans-2,4-dibromo-3-oxo-8-azabicyclo[3.2.1]octane-8-carboxylate (5) in 99% yield, a product that on Favorskii rearrangement
溴化(的CuBr 2,乙酸乙酯/ CHCI 3)加法沃尔斯基重排反应的(EtONa,乙醇)ñ -carbethoxytropinone(4),可容易地从托品酮(3),得到的混合物外-和内切-2,7-二乙酯的异构体-7-氮杂双环[2.2.1]庚烷(1b),化学收率中等(最大37%)。化合物4的溴化反应(Br 2,HBr / AcOH)得到反式-2,4-二溴-3-氧代-8-氮杂双环[3.2.1]辛烷-8-羧酸乙酯(5)的收率达99%,该产品经Favorskii重排(EtONa / EtOH)得到中等收率的2,2-二乙氧基-3-氧代-8-氮杂双环[3.2.1]辛烷-8-羧酸乙酯(6)(52 %)。