In a large bowl, dissolve yeast in warm water. Add the sugar, salt, butter, sour cream and eggs. Beat until smooth. Add 3 cups flour; mix well. Stir in the remaining flour. Cover and refrigerate for 6 hours or overnight.
Punch dough down. Turn onto a floured surface; divide into four pieces. Roll each into a 10-in. circle; cut each circle into 12 wedges. Roll up wedges from the wide end and place point side down 3 in. apart on greased baking sheets. Curve ends to form a crescent. Cover and let rise in a warm place until doubled, about 1-1/2 hours.
Bake at 375° for 15 minutes or until golden brown. Remove from pans to wire racks.