3-[(2R,3S,5R,6S)-5-Benzyloxy-6-benzyloxymethyl-3-(naphthalen-2-ylmethoxy)-tetrahydro-pyran-2-yl]-2-[(4aR,6S,7R,8aS)-2,2-di-tert-butyl-6-(2-hydroxy-ethyl)-4a,6-dimethyl-hexahydro-1,3,5-trioxa-2-sila-naphthalen-7-yloxy]-propionitrile