Can I start working after filing the h4 to h1 even though my old h1 is cap exempt?

[Dumbi]

My original h1 got picked in lottery and approved in 2014. Since then i was working but recently my h1 extention got denied in dec2017 and immedietly i went on h4 status by visiting home country for stamping in Jan 2018.

Now My questions is i have job opportunity in my hand. So, Can i file h4 to h1 (new petition) and start working immedietly or should I wait till I receive my the approval and then start working.

Thanks,
Hema