用反Diels-Alder反应合成天然产物 X IV.立体控制合成(±)-环氧菌素和(±)-4-表环氧菌素

Natural Products Synthesis by Retro Diels-Alder Reaction XIV. Stereospecific Synthesis of (±)-Epoformin and (±)-Epiepoformin

对苯醌与环戊二烯经Diels-Alder反应保护其一侧的双键,在引入必要的官能团及取代基后,再经反Diels-Alder反应得到(±)-4-表环氧菌素(7),对7进一步进行羟基构型转换而得(±)-环氧菌素(6)总产率分别为70%和65%.

p - Benzoquinone reacted with cyclopentadiene to mask its double bond. After introduction of the necessary functional groups and substituent, retro Diels - Alder reaction gave(±) - epiepoformin, which was converted into (±) - epoformin by inversion of its hydroxy configuration in 70% and 65% overall yields, respectively.