So I show that here, so in green, you have what's called a carboxcylic acid group, a c o o h, which gets converted by s o c l 2 to a c double bond o c l or an acid chloride.

我在这里用绿色表示，我们所说的羧酸族化合物，碳，氧，氧，氢，它被亚硫酰氯转化为,一个碳氧双键与碳氯单键组成的酰氯。

麻省理工公开课 - 化学原理课程节选

In this case we have a double bond between a and b, and in this case we have it between b and c.

在这种情况下，我们在，A，与，B，之间有一个双键，而在这种情况下，双键在，B，与，C，之间。

麻省理工公开课 - 化学原理课程节选