Roasted Pork Tenderloin with Pineapple-Chipotle Sauce

2 cups pineapple juice
1/2 cup white wine vinegar
2 tablespoons chipotle chiles, finely chopped
2 tablespoons lime juice
2 tablespoons fresh oregano, chopped, or 2 teaspoons dried
Freshly ground black pepper, to taste
2 teaspoons kosher salt
1 tablespoon coarsely ground black pepper
2 tablespoons chili powder
24 ounces pork tenderloin
1 teaspoon olive oil

Combine first 3 ingredients in saucepan. Simmer until mixture is thick enough to coat back of spoon (30 to 40 minutes) stirring often. Remove from heat and add lime juice, oregano and pepper to taste.

Preheat oven to 400 degrees F.

In small bowl combine salt, pepper and chili powder. Rub tenderloins with mixture.

Heat oil in saut