X-ray studies of 6,7-dihydroxy-1-(2-methoxypropyl)-1,2,3,4-tetrahydroisoqui
nolinium chloride hydrate, C13H20NO3+. Cl-. H2O, show that the saturated pa
rt of the rings has a deformed half-chair conformation, with an axially att
ached 2-methoxypropyl group. The structure is ionic with a net of hydrogen
bonds.