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 (2R,3R,4S,5S)-2-[2-[ethyl(piperidin-2-yl)amino]-6-(pentan-3-ylamino)purin-9-yl]-5-(3-propyl-1,2-oxazol-5-yl)oxolane-3,4-diol .
user
C27H42N8O4
assistant