S 98 Synthesis of (2s,4s)-4-phenylamino-5-oxoproline derivatives [Text] / I. A. Nizova, V. P. Krasnov, G. L. Levit, M. I. Kodess // Amino Acids. - 2002. - Vol. 22, № 2. - P179-186. - Bibliogr. : p. 186 (5 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): AMIDES -- PEPTIDES -- AMINO ACIDS -- PYROGLUTAMIC ACID -- NMR SPECTROSCOPY -- PROTECTING GROUPS Аннотация: The paper describes the synthesis of (2S,4S)-4-(N-Ts)- and (2S,4S)-4-(N-Boc)-phenylamino-5-oxoprolines (pyroglutamic acid). These derivatives have been shown to be useful for synthesis of their amides and peptides in spite of steric hindrances caused by bulky groups adjacent to the reaction centre. Under the conditions applied no lactam ring opening and no loss of stereochemical integrity of any of the chiral centres were observed, which has been confirmed by NMR techniques. |