(1S,3S,3aS,4R,4aS,8aR,9aS)-3-ethyl-dodecahydro-1-methoxy-4-[(phenylthio)methyl]naphtho[2,3-c]furan

(1S,3S,3aS,4R,4aS,8aR,9aS)-3-ethyl-dodecahydro-1-methoxy-4-[(phenylsulfonyl)methyl]naphtho[2,3-c]furan

(2R,6S)-2-[2-Benzenesulfonyl-1-benzoyloxy-2-((1S,3S,3aS,4R,4aS,8aR,9aS)-3-ethyl-1-methoxy-dodecahydro-naphtho[2,3-c]furan-4-yl)-ethyl]-6-methyl-piperidine-1-carboxylic acid tert-butyl ester