running a block of jobs not in parallel

Jenkins
1

So, I know it’s a weird question
I have this code:

parallelTests['1'] =
{
    DO_SOMETHING
}
parallelTests['2'] =
{
    DO_SOMETHING2
}
parallel parallelTests

but I want to add another option, to run this 2 (DO_SOMETHING and DO_SOMETHING2) but not in parallel…
how can I iterate over the parallelTests dictionary and run then one after the other?