(1aS,1bS,2S,5aS,6aS)-Methyl 2-((tert-butyldimethylsilyl)oxy)-1a-(hydroxymethyl)-1a,1b,2,5a,6,6a-hexahydrooxireno[2',3':4,5]cyclopenta[1,2-c]pyran-5-carboxylate