Synthesis of (+)-(4<i>S</i>, 8<i>R</i>)hyphen;8hyphen;Epi- and (−)-(4<i>R</i>, 8<i>S</i>)-4-Epi-β-bisabolol
作者:Georg Fráter、Urs Müller
DOI:10.1002/hlca.19890720405
日期:1989.6.14
total enantioselective synthesis of (+)-(4S, 8R)-8-epi-β-bisabolol(+)-1 and of (−)-(4R, 8S)-4-epi-β-bisabolol ((−))−1) is reported. The key step in the synthesis is the kinetic resolution of (±)−5 by means of the Sharpless epoxidation yielding (−)- and (+}−6, respectively. Reduction of the epoxides with LiAlH4 gave the diols (+)-and(−)−7 which were transformed into (+)- and (−)−8, respectively, via
(+)-(4 S,8 R)-8-epi-β-bisabolol(+)- 1和(-)-(4 R,8 S)-4-epi-β-的第一个全对映选择性合成报告了比沙波洛((-))- 1)。合成中的关键步骤是通过(Sharpless)环氧化反应分别产生(-)-和(+}- 6的动力学拆分(±)-5,用LiAlH 4还原环氧化物得到二醇(+)-和(−)− 7分别通过相应的甲磺酸盐转化为(+)-和(−)− 8。这些环氧化物与格氏试剂的反应在Li 2 CuCl 4的辅助下,由异戊烯基溴化物衍生的H2O3试剂完成了高非对映和对映选择性的目标化合物1的合成。