(3aR,5R,5'S,6S,6aR)-3'-benzyl-2,2,5'-trimethyl-5-vinyldihydro-5H-spiro[furo[2,3-d][1,3]dioxole-6,4'-oxazolidin]-2'-one

(1'R,3'R,4S,5S)-3-benzyl-1',3'-dihydroxy-5-methyl-6'-(trimethylsilyl)-3a',4'-dihydro-1'H-spiro[oxazolidine-4,2'-pentalene]-2,5'(3'H)-dione