X-ray crystallographic analysis of the title hydro-bromide salt, C 10H20N+·Br-, of (1R,2S,3R,5R,8aR)-3-hydroxy-meth-yl-5-methyl-octa-hydro-indolizine-1,2-diol defines the absolute and relative stereochemistry at the five chiral centres in steviamine, a new class of polyhydroxy-lated indolizidine alkaloid isolated from Stevia rebaudiana (Asteraceae) leaves. In the crystal structure, mol-ecules are linked by inter-molecular O- H⋯Br and N- H⋯Br hydrogen bonds, forming double chains around the twofold screw axes along the b-axis direction. Intra-molecular O- H⋯O inter-actions occur.
