A:2
B:﹣1
C:1
D:﹣2
辣椒素是辣椒的活性成分,可以预防心脏病,也能缓解肌肉关节疼痛。辣椒素中酯类化合物的结构可以表示为:
(R为烃基)。其中一种辣椒素酯类化合物J的合成路线如下:
已知:
①A、B和E为同系物,其中B的相对分子质量为44,A和B核磁共振氢谱显示都有两组峰;
②化合物J的分子式为C15H22O4;
③ +H2O
回答下列问题:
我会数,我会填。
山共有____画,笔顺是____。
Nice to meet you. My name is Sally Simpson. Sally is my first name. Simpson is my last name. I'm in Huangzhou, China now. I'm a student in HZFL Middle School. My classroom is very nice. My telephone number is 832—4895.
Good morning! I'm Wu Lei. My first name is Lei and my last name is Wu. I'm in Macheng now. I'm a student in HY Middle School. My phone number is 291—5638. And my QQ number is 83250194.
Hi! My name is Dong Huixia. I'm an English teacher in JM Middle School, Huangmei. I like (喜欢) my students. I'm their good friend. My telephone number is 338—0479.
Hello! My name is Mike Brown. I'm in Wuxue, China now. I'm a student in SY Middle School. My telephone number is 625—1899. And my QQ number is 389410663. My parents are in the school, too.