The invention discloses optically active compounds of Formula (1a) or Formula (1b), wherein R1 and R2 are independently selected from the group consisting of hydrogen and a halogen selected from the group consisting of fluorine, chlorine, bromine, and iodine; and wherein (a) R3 and R4 are independently selected from the group consisting of hydrogen and an alkyl group having a linear or branched chain having 1 to 20 carbon atoms, or (b) R3 and R4 together form a cycloalkyl ring having 3 to 10 carbon atoms fused to the thiophene ring; and wherein R5 is CN or COOR′, where R′ is methyl or ethyl. The compounds of Formula (1a) or Formula (1b) may be used in pharmaceutical compositions for treating fungal infections.