Benzoic acid (3aR,5S,7R,7aR)-7-(tert-butyl-dimethyl-silanyloxy)-2,2-dimethyl-hexahydro-benzo[1,3]dioxol-5-yl ester

(1R,4S,4aR,5R,6S,7S,8aS)-5-tert-butyldimethylsiloxy-6,7-O-isopropylidenedioxy-1,4,4a,5,6,7,8,8a-octahydro-endo-1,4-methano-naphthalen-8-one