Enantioconvergent synthesis of (+)-estrone from racemic 4-tert-butoxy-2-cyclopentenone
作者:Tsutomu Sugahara、Kunio Ogasawara
DOI:10.1016/0040-4039(96)01688-7
日期:1996.10
(+)-Estrone has been synthesized in an enantioconvergent manner fromracemic 4-tert-butoxy-2-cyclopentenonevia contrasteric Diels-Alder reaction and lipase-mediated kinetic transesterification as the key steps.
Contra-steric Diels-Alder route to 3-oxodicyclopentadiene and meso 3,5-endo-dihydroxy-4,5-dihydrodicyclopentadiene
作者:Tsutomu Sugahara、Kunio Ogasawara
DOI:10.1016/0040-4039(95)02129-9
日期:1996.1
Diels-Alderreaction between cyclopentadiene and 4-tert-butoxycyclopentenone occurs in a contra-steric manner to give more hindered endo-3-tert-butoxydicyclopentadiene as the major product (∼15:1) in excellent yield. The product has been transformed into either (±)- and (−)-3-oxodicyclopentadiene or meso 3,5-endo-dihydroxy-4,5-dihydrodicyclopentadiene efficiently.