N-[(2R,3S,4R,5S,6S)-4,5-Bis-benzyloxy-6-benzyloxymethyl-2-((3aR,5S,5aR,8aR,8bR)-2,2,7,7-tetramethyl-tetrahydro-bis[1,3]dioxolo[4,5-b;4',5'-d]pyran-5-ylmethoxy)-tetrahydro-pyran-3-yl]-acetamide