Dos Santos, 19, admitted: "I love Tottenham's plans, they are very ambitious. I was interested in joining them because they are a team that can compete with the top clubs.
"I know Juande Ramos and, of all the offers I had, this was the most challenging from a sporting point of view."
The Dos Santos transfer will be completed when the Mexican has undergone a medical.
But he will not have any work permit problems as he is now a naturalized Spaniard after signing for Barcelona at the age of 13.