It's also got the carboxylic acid though, so let's go ahead and call it butenoic acid.

不过它也含有羧酸， 所以让我们继续称之为丁烯酸。

The most weighted of all is the carboxylic acid functional group, so no matter what else is on a six carbon chain, if there's a carboxylic acid, then it's a hexanoic acid.

最重要的是羧酸官能团，所以无论六碳链上还有什么， 如果有羧酸， 那么它就是己酸。