(R)-2-[(2R,5S,2'S,5'S)-5'-((2R,5S,6R)-6-But-3-enyl-2,6-dimethyl-5-triisopropylsilanyloxy-tetrahydro-pyran-2-yl)-2-methyl-octahydro-[2,2']bifuranyl-5-yl]-4-((R)-2,2,5,5-tetramethyl-[1,3]dioxolan-4-yl)-butan-2-ol