Compounds of Formula I: wherein: R1 and R1′ are independently selected from hydrogen, halogen, C1-to-C12 linear or branched hydroxyalkyl, C1-to-C12 linear or branched halo-alkyl, carboxy, carboxyalkyl, amido, N-alkylamido, N,N-dialkylamido, carbamoyloxy, N-alkylcarbamoyloxy, and N,N-dialkylcarbamoyloxy, provided that that R1 and R1′ are not simultaneously hydrogen; R2 and R2′ hydrogen, halogen, C1-to-C12 linear or branched hydroxyalkyl, C1-to-C12 linear or branched halo-alkyl, carboxy, carboxyalkyl, amido, N-alkylamido, N,N-dialkylamido, carbamoyloxy, N-alkylcarbamoyloxy, and N,N-dialkylcarbamoyloxy, provided that that R2 and R2′ are not simultaneously hydrogen; R3 is selected from hydrogen, C1 to C12 linear or branched alkyl, and nitrogen protecting groups; X is oxygen or nitrogen; when X is oxygen, R4 is absent; and when X is nitrogen, R4 is selected from H, C1-to-C12 linear or branched alkyl, and nitrogen protecting groups.