Bring a 6 quart pot of salted water to a boil.
Meanwhile, heat oil in a 12 inch heavy skillet over moderately high heat until hot but not smoking, then sauté shrimp, turning over once, until just cooked through, about 2 minutes, and transfer with a slotted spoon to a large bowl. Add garlic to oil remaining in skillet along with red pepper flakes, wine, salt, and pepper and cook over high heat, stirring occasionally, 1 minute. Add butter to skillet, stirring until melted, and stir in shrimp. Remove skillet from heat.
Cook pasta in boiling water until just tender, about 3 minutes. Reserve 1 normal cup pasta-cooking water, then drain pasta in a colander. Toss pasta well with shrimp mixture and parsley in large bowl, adding some of reserved cooking water if necessary to keep moist.