Ring Reversal of a Spirocyclic Patchouli Odorant: Molecular Modeling, Synthesis, and Odor of 6-Hydroxy-1,1,6-trimethylspiro[4.5]decan-7-one
作者:Philip Kraft、Audrey Bruneau
DOI:10.1002/ejoc.200600815
日期:2007.5
recently discovered high-impact patchouli odorant (+)-(1S,4R,5R,9S)-1-hydroxy-1,4,7,7,9-pentamethylspiro[4.5]decan-2-one (1) indicated that ring reversal of the spirocyclic system should lead to molecules in which two of the five methyl substituents could be spared without significantly affecting the overall shape or conformational equilibrium. Intramolecular ene reactions promised simple access to the
最近发现的高影响广藿香气味剂 (+)-(1S,4R,5R,9S)-1-hydroxy-1,4,7,7,9-pentamethylspiro[4.5]decan-2-one 的分子建模计算( 1)表明螺环系统的环反转应该导致分子中五个甲基取代基中的两个可以被保留,而不会显着影响整体形状或构象平衡。分子内烯反应有望轻松获得所需的目标化合物,(5R*,6R*)-6-hydroxy-1,1,6-trimethylspiro[4.5]decan-7-one(2),但所有尝试均以失败告终。目标结构 2 的详细替代六步合成开始于将 HCl 气体添加到 5-溴-2-甲基-2-戊烯 (16),得到 1-溴-4-氯-4-甲基戊烷 (15)。通过 TiCl4 介导的 TMS 烯醇化物 14 烷基化和随后通过 tBuOK 环化,环己酮与该结构单元的螺环化得到 1,1-二甲基螺[4.5] decan-6-one (12)。这种螺环酮与