for the following products
(R)-2-(tert-Butoxycarbonylamino)-3-methoxypropanoic acid | D-Serine, N-[(1,1-dimethylethoxy)carbonyl]-O-methyl- | N-[(1,1-Dimethylethoxy)carbonyl]-O-methyl-D-serine | O-Methyl-N-{[(2-methyl-2-propanyl)oxy]carbonyl}-D-serine and Boc-O-Methyl-D-serine
