Synthesis and reductions of (1R,4E,5S)-4-oximino-1,8,8-trimethyl-2-oxabicyclo[3.2.1]octan-3-one
作者:Uroš Grošelj、David Bevk、Renata Jakše、Anton Meden、Branko Stanovnik、Jurij Svete
DOI:10.1016/j.tetasy.2005.04.026
日期:2005.6
(1R,4E, 5S)-4-Oximino-1,8,8-trimethyl-2-oxabicyclo[3.2.1]octan-3-one 9 was prepared in three steps from (1R)-(+)-camphor 1 via nitrosation of(1R,4E,5S)-4-[(diinetliylamino)methylidene]-1,8,8-trimethyl-2-oxabicyclo[3.2.1]octan-3-one 8. Catalytic hydrogenation of 9 under various reaction conditions afforded (1R,4S, 5S)-4-amino-1, 8,8-trimethyl-2-oxabicyclo[3.2.1]octan-3-one derivatives 11, 13, and 15b. On the other hand, reduction of 9 with Grignard reagents led to two types of products, (lR,4S,5S)4-dialkylamino-1,8,8-trimethyl-2-oxabicyclo[3.2.1]octan-3-ones 15b and 15c and/or 2-substituted (1E)-1-[(1S,3R)-3-hydroxy-2,2,3-trimethylcyclopentyllethane-1,2-dione 1-oximes 16a,b and 15d-f. The structures of compounds 9, 10' 15b, and 16b were determined by X-ray diffraction. (c) 2005 Elsevier Ltd. All rights reserved.
(1R,4E,5S)-4-氧亚胺基-1,8,8-三甲基-2-氧杂双环[3.2.1]辛-3-酮 9 是通过三步反应从 (1R)-(+)-樟脑 1 开始合成的,其中关键步骤是(1R,4E,5S)-4-[(二甲基亚氨基)亚甲基]-1,8,8-三甲基-2-氧杂双环[3.2.1]辛-3-酮 8 的亚硝化反应。在不同的反应条件下,对 9 进行催化解氢还原,得到 (1R,4S,5S)-4-氨基-1,8,8-三甲基-2-氧杂双环[3.2.1]辛-3-酮衍生物 11、13 和 15b。另一方面,以 Grignard 试剂对 9 进行还原反应,得到了两种类型的产品,分别为 (1R,4S,5S)-4-双烷基氨基-1,8,8-三甲基-2-氧杂双环[3.2.1]辛-3-酮 15b 和 15c,以及 2-取代的 (1E)-1-[(1S,3R)-3-羟基-2,2,3-三甲基环戊基]乙烷-1,2-二酮-1-亚胺 16a、b 和 15d-f。化合物 9、10'、15b 和 16b 的结构通过 X 射线衍射确定。© 2005 Elsevier Ltd. 保留所有权利。