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

(2S,6R)-2-Methyl-6-[(E)-2-((3S,3aR,4S,4aR,8aR,9aS)-3-methyl-1-oxo-dodecahydro-naphtho[2,3-c]furan-4-yl)-vinyl]-piperidine-1-carboxylic acid tert-butyl ester