You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3S,5R,6R)-3-[(3,4-dimethoxyphenyl)methyl]-5-(hydroxymethyl)-3-methyl-6-phenylmorpholin-2-one;hydrochloride is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H26ClNO5
assistant