acid hydrolysis yielded the tetralone IIIa and the latter was carboxymethylated to IIIb by reaction with dimethyl carbonate and sodium hydride. Michael condensation of IIIb with methyl vinyl ketone yielded the unsaturated ketone IV. The tricyclic ketone IV on methylation followed by thioketalisation gave the thioketal IXa and the latter on Raney nickel desulfurisation yielded Ic.
2,7-二甲氧基-3-
异丙基萘 (IIb) 本身由 IIa 分五步进行 Birch 还原,然后酸
水解得到四氢
萘酮 IIIa,后者通过与
碳酸二甲酯和氢化
钠反应羧甲基化为 IIIb . IIIb与甲基
乙烯基酮的迈克尔缩合产生不饱和酮IV。甲基化后的
三环酮 IV 得到
硫缩酮 IXa,而后者在 Raney
镍脱
硫中得到 Ic。