(4R,5S)-5-Ethynyl-2,2-dimethyl-[1,3]dioxolane-4-carbaldehyde

(3aS,9aR,10S,10aR)-2,2-dimethylhexahydro-4H-[1,3]dioxolo[4,5]pyrido[1,2-c][1,3]oxazin-10-yl methanesulfonate

(3aS,8aR,9aR)-2,2-Dimethyl-tetrahydro-1,3,6-trioxa-4a-aza-cyclopenta[b]naphthalen-9-one

(3aS,9aR,10S,10aR)-10-(hydroxymethyl)-2,2-dimethylhydro-4H-[1,3]dioxolo[4,5]pyrido[1,2-c][1,3]oxazin-10-ol

3-{[(4S,5S)-5-ethynyl-2,2-dimethyl-1,3-dioxolan-4-yl]methylamino}-3-(trimethylsilyl)propan-1-ol