You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule (1S,2R,8S)-10-phenanthren-9-yl-14-oxa-7-azatetracyclo[6.6.1.01,11.02,7]pentadeca-9,11-dien-13-one ?
user
C27H23NO2
assistant