synthetic steps. Intermolecular Diels–Alder reaction of 6 with diene 7, cyclodehydrogenation catalyzed by iodine-dimethyl sulfoxide, and sodium dithionite reduction were the key steps. The absolute configuration of natural parimycin was determined to be S.
(±)-parimycin和(R)-parimycin的第一批总合成是从O- methylnaphthazarin(6)分九个合成步骤完成的。关键的步骤是分子间Diels–Alder反应6与二烯7,
碘-
二甲基亚砜催化的环脱氢反应和
连二亚硫酸钠还原。测定自然parimycin的绝对构型是小号。