(2'R,3'S,6'S,8'S,10'R)-(E)-(+)-ethyl 4-(10'diphenyl-t-butylsiloxy-2',3'-dimethyl-1',7'-dioxaspiro<5.5>undecane-8'-yl)-2-methylbut-2-enoate

2-Oxazolidinone,3-[6-[4-[[(1,1-dimethylethyl)diphenylsilyl]oxy]-8,9-dimethyl-1,7-dioxaspiro[5.5]undec-2-yl]-2,4-dimethyl-1-oxo-4-hexenyl]-4-(1-methylethyl)-,[2R-[2a[1(R*),2R*,4Z],4a,6b(8R*,9S*)]]-