(R)-Semixanthomegnin (8), which has been converted by others to the mould metabolite (3R,3′ R)-xanthomegnin (9), is prepared in seven steps from (R)-propylene oxide (16). A single-crystal X-ray structure analysis of (±)-7-chloro-10-methoxy-3-methyl-3,4-dihydro-1H-naphtho[2,3-c]pyran-1,6,9-trione (25) confirms the regiochemistry of the cycloaddition reaction between 2,5-dichloro-1,4-benzoquinone and
(R)-Semixanthomegnin (8)是由(R)-环氧
丙烷(16)经七个步骤制备而成的,它已被其他人转化为霉菌代谢物(3R,3′R)-xanthomegnin (9)。对(±)-7-
氯-10-甲氧基-3-甲基-3,4-二氢-1H-
萘并[2,3-c]
吡喃-1,6,9-三酮(25)的单晶 X 射线结构分析证实了
2,5-二氯-1,4-苯醌与新的、高含氧手性
丁二烯衍
生物(2)之间环化反应的区域
化学性质。