(2S,3aR,8aS)-3a-Hydroxy-1-trityl-1,2,3,3a,8,8a-hexahydro-pyrrolo[2,3-b]indole-2-carboxylic acid tert-butyl ester

(2S,3aR,8aS)-3a-Hydroxy-3,3a,8,8a-tetrahydro-2H-pyrrolo[2,3-b]indole-1,2-dicarboxylic acid 2-tert-butyl ester 1-(9H-fluoren-9-ylmethyl) ester