Table 1.

Specific optical rotations of PAA-Val and PPAA-Val in different solvents.

Compound	[${\mathsf{\alpha }}_{\mathbf{D}}^{\mathbf{20}}$]/° a
	CHCl3	MeOH	DMF	DMAc	THF	Acetone
PAA-Val	+57.6	+10.3	+40.6	+40.0	+25.3	+39.3
PPAA-Val	+433	+334	+515	+453	+557	+457

^a Measured by polarimetry at room temperature (c = 1 mg/mL).