(2S,3S,4S,7S,E)-4,7-bis((tert-butyldimethylsilyl)oxy)-2-methyl-10-oxo-3,4,7,8,9,10-hexahydro-2H-oxecin-3-yl methanesulfonate

(1R,2S,7S,10S,E)-2-methyl-4-oxo-3,11-dioxabicyclo[8.1.0]undec-8-en-7-yl 4-nitrobenzoate

(5R,8S,9R,10S,E)-5,8,9-trihydroxy-10-methyl-3,4,5,8,9,10-hexahydro-2H-oxecin-2-one

(5R,8S,9S,10S,E)-5,8-bis(tert-butyldimethylsilyloxy)-9-hydroxy-10-methyl-3,4,5,8,9,10-hexahydro-2H-oxecin-2-one