The X-ray crystal structure of 2-tert-butylindolizine-3-selenoaldehyde

The title compound is the first crystallographically characterised uncomplexed selenoaldehyde. The indolizine ring and selenocarbonyl group are coplanar with each other, the carbon–selenium bond length [1.808(5) Å] is essentially identical to those observed in selenoketones. The indolizine rings are stacked in the lattice with their planes parallel within the layers.