Alberto Vilar, the philanthropist and opera-lover who has donated more than $300 million to arts organizations around the world, has missed mortgage payments on three vacation homes in Colorado, and local banks are foreclosing. Vilar, who was one of the first investors on the high-tech bandwagon of the 1990s, appears not to have gotten off in time to avoid heavy investment losses. In recent months, he has missed payments to several arts organizations to which he had pledges outstanding, and the current overdue mortgage payments reportedly total $2.74 million. Vilar is said to be furious with the banks’ decision to foreclose.