You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule methyl (2Z,3E,5E,9E)-2-ethylidene-11-(4-hydroxy-4-methyl-2-oxo-6-oxa-3-azabicyclo[3.1.0]hexan-1-yl)-4,10-dimethyl-11-oxoundeca-3,5,9-trienoate .
user
C21H27NO6
assistant