| 摘要 |
A method of producing alkyl 3-hydroxy-4-(4-hydroxyphenoxy)pentanoate which comprises the steps of: (a) reacting 4-benzyloxyphenol with an alkali hydroxide and 2-chloropropionic acid in the presence of a suitable solvent and at a temperature sufficient to cause formation of 2-(4-benzyloxyphenoxy)propionic acid; (b) reacting said 2-(4-benzyloxyphenoxy)propionic acid with a compound selected from phosgene, oxalyl chloride, thionyl chloride, or phosphorus trichloride, in the presence of a suitable catalyst and solvent and at a temperature sufficient to cause formation of 2-(4-benzyloxyphenoxy)propionyl chloride; (c) reacting said 2-(4-benzyloxyphenoxy)propionyl chloride with 2,2-dimethyl-1,3-dioxan-4,6-dione and pyridine, all in the presence of a suitable solvent and at a temperature sufficient to cause formation of 5-[2-(4-benzyloxyphenoxy)propionyl]-2,2-dimethyl-1,3-dioxan-4,6-dione; (d) reacting said 5-[2-(4-benzyloxyphenoxy)propionyl]-2,2-dimethyl-1,3-dioxan-4,6-dione with an alkyl alcohol for a period of time and at a temperature sufficient to cause formation of alkyl 4-(4-benzyloxyphenoxy)-3-oxopentanoate; (e) reacting said alkyl 4-(4-benzyloxyphenoxy)-3-oxopentanoate with sodium borohydride in the presence of a suitable solvent and at a temperature sufficient to cause formation of alkyl 4-(4-benzyloxyphenoxy)-3-hydroxy-pentanoate; and (f) reacting said alkyl 4-(4-benzyloxyphenoxy)-3-hydroxypentanoate with hydrogen in the presence of a suitable solvent, a suitable catalyst, and at a sufficient temperature to form the desired product, alkyl 3-hydroxy-4-(4-hydroxyphenoxy)pentanoate.
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