Asymmetric oxidation of β-ketoesters with benzoyl peroxide; enantioselective formation of protected tertiary alcohols
作者:Junning Lee、Shunichi Oya、John K. Snyder
DOI:10.1016/s0040-4039(00)79421-4
日期:1991.10
Asymmetric oxidation of β-ketoesters by the benzoylperoxide quench of their lithioenamines formed with (S)-valine-t-butyl esters has been accomplished with good enantioselectivity for the formation of tertiary benzoate esters. This procedure thus enables generation of tertiary alcohols in protected form.
Total synthesis of herbertenediol, an isocuparane-sesquiterpene possessing a potent anti-lipid peroxidation activity isolatedfrom a liverwort, has been achieved via herbertenol using intramolecular Heck reaction as the key step.
(-)-Herbertenediol (3) which is regarded as a biosynthetic precursor of mastigophorenes A and B has been effectively synthesized from (R)-1,2-dimethyl-2-cyclopentene carboxylic acid by applying an intramolecular Heck reaction to the construction of the quaternary carbon center, and then horseradish peroxidase-catalyzed oxidative coupling of 3 has given rise to (-)-mastigophorenes A and B. Mastigophorenes A and B have been found to exhibit significant neuroprotective activity in primary cultures of fetal rat cortical neurons. (C) 2001 Elsevier Science Ltd. All rights reserved.