M. Omote et al., OPTICAL RESOLUTION AND ASYMMETRIC-SYNTHESIS OF BENZYL ,2-TRIFLUORO-1-HYDROXYETHYL)-PYRROLE-2-CARBOXYLATE, Heterocycles, 47(1), 1998, pp. 65-68
For the total synthesis of 3- and 8-(2,2,2-trinuoro-1-hydroxyethyl)-de
uteroporphyrin dimethyl esters (2, and 3) in a large scale by ring clo
sure, the camphanyl ester (5) of the titled ester (4) was resolved, bu
t hydrolysis Of the resolved 5 was unsuccessful. Oxidation of 4 with D
ess-Martin reagent gave 3-trifluoromethylcarbonyl compound (6), which
was reduced with catecholborane in the presence of a chiral catalyst t
o a chiral isomer of 4 in a high enantiomeric excess.