(2R,3S,7R,9S,10S,11R)-10-[(2S,3R,4S,6R)-4-dimethylamino-3-hydroxy-6-me thyl-oxan-2-yl]oxy-2-ethyl-3-hydroxy-3,7,9,11-tetramethyl-1-oxacyclodo dec-4-ene-6,12-dione