Syntheses of ()-1, 4, 7, 10-tetraoxaspiro [5.5] undecane (spirobi-1, 4-dioxan),()-1, 4, 7-trioxa- 10-thiaspiro [5.5] undecane, and ()-1, 4, 7-trioxa-10-azaspiro [5.5] undecane from 2′- chloroethyl--fructopyranoside are reported, in which the chirality of the spiro-ring junction is defined by the configuration of the anomeric car
