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 (8aS)-7-(6-methyl-2-pyrrolidin-1-ylpyrimidin-4-yl)-5,6,8,8a-tetrahydro-1H-[1,3]oxazolo[3,4-a]pyrazin-3-one .
user
C15H21N5O2
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