Synthesis and biocatalytic resolution of a new atropisomeric thiobiphenyl: (2,2 ',6,6 '-tetramethoxybiphenyl-3,3 '-diyl)dimethanethiol

Both atropisomers of racemic thiobiphenyl (±)-1 were obtained in enantiopure form using lipase catalysed procedures. The esterification reaction of (±)-1 in the presence of vinyl acetate gave in a one-pot reaction (+)-1 and (-)-1 via a lipase assisted dynamic kinetic resolution of epimerizing hemithioacetal intermediates. The alcoholysis of the diacetylthioester, (±)-5, is an alternative strategy for access to the enantiomers of 1 with high enantiomeric excess.