GO:0018812:   3-hydroxyacyl-CoA dehydratase activity
Catalysis of the reaction: alkene-CoA + H2O = alcohol-CoA. Substrates are crotonoyl-CoA (producing 3-hydroxyacyl-CoA) and 2,3-didehydro-pimeloyl-CoA (producing 3-hydroxypimeloyl-CoA).