1.These on reduction with NaBH4 gave exclusively cis-3-heterocycle substituted chroman-4-ols in good yields.
【
】3,3-Dibromochroman-4-ones on reaction with different heterocyclic secondary amines gave 3-substituted chromones.
明：以上例句、词性分类均由互联网资源自动生
，部分未经过人工审核，其表达内容亦不代表本软件
观点；若发现问题，欢迎向我们指正。
