英语语法分析

6-Hydroxychroman was prepared by catalytic hydrogenation of 6-hydroxy-4-chromone, which was prepared via condensation of 2′, 5′-dihydroxyacetophenone with triethyl ortho-formate.

前言： 以2′，5′-二羟基苯乙酮和原甲酸三乙酯缩合得到6- 羟基- 4- 色酮，再经催化氢化得到标题化合物。