2H-Pyran-2-ethanol, tetrahydro-6-methoxy-b,3,5-trimethyl-,[2S-[2a(R*),3a,5a,6a]]-

7-O-t-butyldimethylsilyl-2,3,4,6-tetradeoxy-5-O-(1-ethoxyethyl)-2,4,6-trimethyl-D-gluco(and manno)-heptose trimethylene dithioacetal