(2E)-3-{(2S,4S,5S,9S)-9-[tert-butyl(dimethyl)silyloxy]-6,6,8-trimethyl-7-(3-methyl-2-oxobut-3-en-1-yl)-2-phenyl-1,3-dioxaspiro[4.5]dec-7-en-4-yl}acrylaldehyde

{(2S,4S,5S,9S)-7-allyl-9-hydroxy-6,6,8-trimethyl-2-phenyl-1,3-dioxaspiro[4.5]dec-7-en-4-yl}methyl acetate

{(2S,4S,5S,9S)-9-[tert-butyl(dimethyl)silyloxy]-6,6,8-trimethyl-7-(2-oxoethyl)-2-phenyl-1,3-dioxaspiro[4.5]dec-7-en-4-yl}methyl acetate

{(2S,4S,5S,9S)-7-allyl-9-[tert-butyl(dimethyl)silyloxy]-6,6,8-trimethyl-2-phenyl-1,3-dioxaspiro[4.5]dec-7-en-4-yl}methyl acetate

1-{(2S,4S,5S,9S)-9-[tert-butyl(dimethyl)silyloxy]-4-[(1E)-3-hydroxyprop-1-en-1-yl]-6,6,8-trimethyl-2-phenyl-1,3-dioxaspiro[4.5]dec-7-en-7-yl}-3-methylbut-3-en-2-one