You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[[(2R,3aS,5R,6R,6aR)-5-(hydroxymethyl)-6-phenylmethoxy-2,3,3a,5,6,6a-hexahydrofuro[3,2-b]furan-2-yl]methyl]prop-2-enamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H23NO5
assistant