(2R,3R,5S,6R)-3-(tert-Butyl-dimethyl-silanyloxy)-5-methoxy-6-methoxymethyl-2-methyl-tetrahydro-pyran-2-carbaldehyde

1-[(2S,3R,5S,6R)-3-(tert-Butyl-dimethyl-silanyloxy)-5-methoxy-6-methoxymethyl-2-methyl-tetrahydro-pyran-2-yl]-4-[(2R,3S)-3-(4-methoxy-benzyloxy)-tetrahydro-pyran-2-yl]-but-2-yn-1-ol