You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Name the molecular formula for the molecule established as (5S,6R,7S,8S)-6-(3-methylbut-2-enoyl)-7-(4-methylphenyl)spiro[1,2,3,6,7,8-hexahydropyrrolizine-5,3'-1H-indole]-2'-one using the IUPAC nomenclature.
user
C26H28N2O2
assistant