Inversion of stereochemistry.
SMARTS: [C;H1&$(C([#6])[#6]),H2&$(C[#6]):1][OH1].[NH1;$(N(C=O)C=O):2]>>[C:1][N:2]
Conditions
R1, R2: ph, alkyl. R3, R4: aryl, alkyl.
References
Mitsunobu, O.; Yamada, M.; Mukaiyama, T.
Bull. Chem. Soc. Jpn. 1967, 40, 935–939.
Mitsunobu, O.; Yamada, M.
Bull. Chem. Soc. Jpn. 1967, 40, 2380–2382.
Other sources
Organic chemistry
Wikipedia