Temperature and solvent effects on enzyme stereoselectivity: Inversion temperature in kinetic resolutions with lipases
Eyring plots of InE vs. 1/T show inversion temperature in kinetic resolution by lipases, demonstrating that clustering effects in the substrate solvation manage the enzymatic selectivity.
A total synthesis of (1R,5R)-3-phenylmethyl-4-thia-2,6-diazabicyclo [3.2.0]hept-2-en-7-one, a useful intermediate for the preparation of penem and cepham derivatives
The preparation of the thiazoline (1R,5R)-3-phenylmethyl-4-thia-2,6- diazabicyclo [3.2.0]hept-2-en-7-one (1) is presented. This compound, which has been extensively used as an intermediate for the synthesis of penems and cephams, has been obtained starting from a C-4 unsubstituted azetidinone by means of facile processes while chirality has been obtained through enzymatic resolution.