(8R,8aS)-8-(tert-butyldimethylsiloxy)-2,3,8,8a-tetrahydro-5(1H)-indolizinone

(S)-2-[(Z)-(S)-1-(tert-Butyl-dimethyl-silanyloxy)-3-ethoxycarbonyl-allyl]-pyrrolidine-1-carboxylic acid tert-butyl ester