4-氧取代的橙酮的1H-NMR特征是

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku where sourceid='26291' and id < 2199405 and id<>'2199405' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='26291' and id > 2199405 and id<>'2199405' order by id asc limit 5