Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... (S)-Alanyl-(R)-2-bromoabryl-(R)-β-tyrosine found in jaspamide(1) was conveniently synthesized as its protected derivative 2 in good yield. ... The two diastereoisomers separated on silica gel thin layer chromatograph developed with etherbenzene, but the separation on column ...