Δ6,7-8,9-O-isopropylidene-1-oxa-spiro[4.5]decan-2-one

5-(tert-butyldiphenylsilanyloxy)-6,7-O-isopropylidene-1-oxaspiro[2.5]octane

8,9-dihydroxy-1-oxa-spiro[4.5]dec-6-en-2-one

3-hydroxy-Δ6,7-8,9-O-isopropylidene-1-oxa-spiro[4.5]decan-2-one

(1R,2S,4R,5R,6R)-4,5-dihydroxydihydro-5'H-7-oxaspiro[bicyclo[4.1.0]heptane-2,2'-furan]-5'-one