Stereocontrolled Syntheses of Kainoid Amino Acids from 7-Azabicyclo[2.2.1]heptadienes Using Tandem Radical Addition-Homoallylic Radical Rearrangement
作者:David M. Hodgson、Shuji Hachisu、Mark D. Andrews
DOI:10.1021/jo0513865
日期:2005.10.1
or aryl)sulfonyl-2-azabicyclo[2.2.1]hept-5-enes serve as precursors in syntheses of the neuroexcitants 3-(carboxymethyl)pyrrolidine-2,4-dicarboxylic acid 43, α-kainic acid 12, α-isokainic acid 14, and α-dihydroallokainic acid 77. The key step in these syntheses is the intermolecular radical addition of 2-iodoethanol to a N-Boc 2-(alkyl or aryl)sulfonyl-7-azabicyclo[2.2.1]heptadiene 7 to induce nitrogen-directed
N -Boc syn -7-(2-羟乙基)-4-(烷基或芳基)磺酰基-2-氮杂双环[2.2.1]庚-5-烯用作神经兴奋剂3-(羧甲基)吡咯烷-的合成前体。 2,4-二羧酸43,α-海藻酸12,α-异钾酸14和α-二氢链烷酸77。这些合成的关键步骤是将2-碘乙醇分子间自由基加成到N -Boc 2-(烷基或芳基)磺酰基-7-氮杂双环[2.2.1]庚二烯7诱导氮定向的均烯丙基自由基重排。所得的2-氮杂双环[2.2.1]庚-5-烯的氧化裂解提供了直接接近多取代的吡咯烷的途径,并且特别是有效地进入了类胡萝卜素氨基酸。