Write down the acyclic isomers having the molecular formula `C_3H_6O`.
Strategy: first calculate the degree of unsaturation or DBEs:
`DBE=(sumn(v-2))/(2)+1`
`=(3(4-2)+6(1-2)+1(2-2))/(2)+1=1`
This means that various acyclic isomers of `C_3H_6O` contain just one double bond, i.e., `C=C` or `C=O`, in the following skeletons:
`C-C-C-O,C-C-O-C,C-underset(O)underset(|)(C)-C`