(5R,6R,7R,9R,13R,14S)-21-Cyclo­propyl­meth­yl-6,14-endo-ethano-2',3',4',5',7,8-hexa­hydro-4',4',5',5'-tetra­methyl­furano[2',3'6,7]normorphide hydro­chloride methanol solvate

The title compound, C₂₈H₃₈NO₃⁺·Cl^-·CH₄O, is demeth­oxy-buprenorphine hydro­chloride (buprenorphine degradation product). Crystal structure determination has confirmed that the elimination of methanol and rearrangement with the formation of a new ring proceeds with the retention of chirality of all chiral centres of the mol­ecule.