立体化学中R、S-构型标记法的教学实践探新

Probe into the R,S-configuration marking Method in Teaching Stereo-chemistry

R、S-标记法是根据手性碳原子所连的4个基团在空间的排列顺序来标记的。其方法是先把手性碳原子所连的4个基团设为a、b、c、d,将4个基团按次序规则排序,若a、b、c、d四个基团的优先次序为a>b>c>d,伸出左手,手臂所在方向代表排在最后的基团d的伸展方向,拇指、食指、中指代表其它3个基团的伸展方向,无名指和小指捏成拳代表手性碳原子,然后手指指向观察者,观察a→b→c的轮转方向,若a→b→c的轮转方向是顺时针方向,则将该手性碳原子的构型标记为"R";如果是逆时针方向,则标记为"S"。

R,S-notation is decided and based on the chiral carbon atoms of the four groups in the order of the space to mark. The method is to handle the four groups of sexual carbon atoms, which are set as a, b, c, d, and are ordered. If a, b, c, d groups of priorities is set for a〉b〉c〉d, when a person can stretch out his left hand and the direction in arm represents the ranking of the stretching direction of group d. Therefore, the thumb and forefinger and middle finger represent the other groups stretching direction,which means ring finger and little finger knead into boxing which is the chiral carbon atoms, and finger points to the observer. Then, he can observe the rotation direction of a〉b〉c. If a〉b〉c in the direction of rotation is clockwise, configuration of the chiral carbon atoms is marked as ＂R＂. If it is anticlockwise, it will be marked as ＂S＂.