Structure of (±)‐egenine

6,8-Dihydro-6-(5,6,7,8-tetrahydro-6-me thyl-1,3-dioxolo[4,5-g]isoquinolin-5-yl)furo[3,4-e]- 1,3-benzodioxol-8-ol, C 20 H 19 NO 6 , M r =369.4, tri clinic, P1, a=10.833 (2), b=13.184 (3), c=13.375 (3) A, a=89.73 (3), b=74.52 (3), γ=71.95 (3) o , V=1744.0 (5) A 3 , Z=4, D x =1.407 g cm -3 , λ(Cu Kα)=1.54178 A, μ=8.30 cm -1 , F(000)=776, room temperature, R=0.051 for 3375 observed reflections. The relative con figuration of the hemiacetal C atom is established. The heterocyclic fragment of isoquinoline exhibits a half-chair conformation; all five-membered rings show envelope conformations