(3aS,8aS)-3a-Methylsulfanylthiocarboxyoxymethyl-2,3,3a,8a-tetrahydro-furo[2,3-b]indole-8-carboxylic acid benzyl ester

(3aR,8aS)-3a-((triethylsilyl)oxy)-3,3a,8,8a-tetrahydro-2H-furo[2,3-b]indole