The unambiguous total synthesis of the lichen depsides
2-O-methylglomelliferic acid (39),
4-O- methylhyperolivetoric acid (40), hyperconfluentic
acid (41), microphyllinic acid (42), arthoniaic acid (43),
2′-O-methylmicrophyllinic acid (44),
2′-O-methylhyperphyllinic acid B (45),
4-O-methylsuperolivetoric acid (46),
2′-O-methylhyperphyllinic acid A (47),
2′-O-methylnorsuperphyllinic acid (48) and
4-O- methyloxocryptochlorophaeic acid (49) has been
achieved by the condensation of an appropriately substituted orsellinic acid
and protected phenol in the key step, followed by deprotection.
地衣苷的明确全合成
2-O-甲基扁桃酸(39)、
4-O-甲基过藜芦酸(40)、高藜芦酸(41)、小藜芦酸(42)、荩草酸(40
酸 (41)、microphyllinic acid (42)、arthoniaic acid (43)、
2′-O-methylmicrophyllinic acid(44)、
2′-O-methylhyperphyllinic acid B (45)、
4-O-甲基苏合香酸(46)、
2′-O-methylhyperphyllinic acid A (47)、
2′-O-methylnorsuperphyllinic acid (48) 和
和 4-O-甲氧基隐绿原酸(49)。
在关键步骤中,通过适当取代的奥塞林酸和受保护的苯酚缩合
和受保护的苯酚进行缩合,然后再进行脱保护。