((2R,4a'R,5R,6'R,7'R,8'R,8a'R)-7'-(benzyloxy)-5-(((tert-butyldiphenylsilyl)oxy)methyl)-8'-(methoxymethoxy)octahydro-3H,3'H-spiro[furan-2,2'-pyrano[3,2-b]pyran]-6'-yl)methanol