(1S,6R)-3-(((tert-butyldiphenylsilyl)oxy)methyl)-5',5'-diethyl-4-((E)-pent-1-en-1-yl)-7-oxaspiro[bicyclo[4.1.0]heptane-2,2'-[1,3]dioxan]-3-en-5-one

(2R,4R)-8-Bromo-7-(tert-butyl-diphenyl-silanyloxymethyl)-2,4-dimethyl-1,5-dioxa-spiro[5.5]undeca-7,10-dien-9-one

(1S,4'R,6R,6'R)-3-(((tert-butyldiphenylsilyl)oxy)methyl)-4',6'-dimethyl-4-((E)-pent-1-en-1-yl)-7-oxaspiro[bicyclo[4.1.0]heptane-2,2'-[1,3]dioxan]-3-en-5-one

(1S,4'R,5R,6S,6'R)-3-(((tert-butyldiphenylsilyl)oxy)methyl)-4',6'-dimethyl-4-((E)-pent-1-en-1-yl)-7-oxaspiro[bicyclo[4.1.0]heptane-2,2'-[1,3]dioxan]-3-en-5-ol

(1S,6R)-4-bromo-3-(((tert-butyldiphenylsilyl)oxy)methyl)-5',5'-diethyl-7-oxaspiro[bicyclo[4.1.0]heptane-2,2'-[1,3]dioxan]-3-en-5-one