Stereoselective reduction of (R,S)-[(η5-C5H5)Fe(CO)(PPh3)(COCH2CH2CMe2)]+ and complete epimerisation of the kinetic (RR,SS)-diastereoisomer to the thermodynamic (RS,SR)-diastereoisomer of the product [(η5-C5H5)Fe(CO)(PPh3){C(H)OCH2CH2CMe2}]

Abstract

Hydride reduction of the cation [(η⁵-C₅H₅)Fe(CO)(PPh₃)([graphic ommitted]Me₂)]⁺ occurs completely stereoselectively to give the kinetic product (RR,SS)-[(η⁵-C₅H₅)Fe(CO)(PPh₃){[graphic ommitted]Me₂}] which subsequently under mild acid conditions epimerises completely to the thermodynamically more stable (RS,SR)-diastereoisomer; a simple conformational analysis rationalises both these phenomena.