(E)-5-((2S,3aR,5R,5'R,6R,6''S,7aR)-2-(((tert-butyldiphenylsilyl)oxy)methyl)-6-methyldecahydro-4''H-trispiro[furo[3,2-b]pyran-5,2'-furan-5',2''-pyran-3'',2'''-[1,3]dithian]-6''-yl)pent-4-en-1-yl pivalate