e. Reduction of the latter with sodium borohydride, followed by carboxylation, gave (±)-1-(4-carboxy-3,5-dihydroxyphenyl)-heptan-2-ol. This reacted readily with ethyl orthoformate to give (±)-pulvilloric acid. Carboxylation of the (+)-heptan-2-ol followed by esterification with diazomethane and treatment with dimethoxymethane gave a very low yield of (±)-methyl dihydropulvillorate.
3,5-二
甲氧基苯基
乙酰氯已被转化为1-(3,5-二
甲氧基苯基)庚-2--2-,然后通过脱甲基化为1-(3,5-二羟基苯基)庚-2-。用
硼氢化钠还原后者,然后羧化,得到(±)-1-(4-羧基-3,5-二羟基苯基)
庚烷-2-醇。这容易与原
甲酸乙酯反应,得到(±)-草
丁二酸。(+)-庚-2-醇的羧化,然后用
重氮甲烷酯化并用二甲氧基
甲烷处理,得到非常低产率的(±)-甲基二氢
丙酮酸甲酯。