the question is in the title. Is it possible?
It is a big yes, it is better to use bitcoin in buying the altcoins because it is the most convenient way especially if you have already keep lot of bitcoins in your wallet and also you will avoid some extra transaction fees if you use fiat or the dollar bill. Using bitcoin to purchase altcoins already exercising the art of trading which is vital to earn a huge amount of bitcoin someday.
Best it would be if implemented. Everyone here wants to earn bitcoins and once we are done with it, we all are mostly waiting for getting more and more.
So better plan it is, to make your bitcoins trade with altcoins and the market will give you two chances for selling altcoins later for bitcoins and you are getting bitcoins at double rate. Hats off!