Table 2.

Yields of carboxylic acid analogs 18–23.

Compound	Compound no	Yield [%]
MPA-Asp-OH	18	87
MPA-Thr-OH	19	88
MPA-D-Thr-OH	20	86
MPA-Ile-OH	21	80
MPA-Arg(NO2)-OH	22	87
MPA-D-Arg(NO2)-OH	23	89