Tetrahedron

Studies on amino acids and peptides-III. 2, 4-bis (4-methoxyphenyl)-1, 3, 2, 4-dithiadiphosphetane 2, 4-disulfide, LR, as a new racemization free coupling reagent in …

U Pedersen, M Thorsen, EEAM El-Khrisy, K Clausen…

Index: Pedersen, U.; Thorsen, M.; El-Khrisy, E. -E. A. M.; Clausen, K.; Lawesson, S. -O. Tetrahedron, 1982 , vol. 38, # 22 p. 3267 - 3269

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Citation Number: 18

Abstract

The easily accessible 2, 4-bis (4-methoxyphenyl)-1, 3, 2, 4-dithiadiphosphetane 2, 4- disulfide, LR, has been reacted with salts of N-protected amino acids 1 (Z-Gly-OH, Boc-Gly- OH, Boc-S-Ser (Bzl)-OH, Boc-S-Tyr (Bzl)-OH, ZS-Arg (Z2)-OH, and ZS-Pro-OH), at room temperature in CH2Cl2 to give the intermediates 2, mixed anhydrides. When 2 is treated with two moles of a base and one mole of the salt of an amino acid ester 3 (TosOH· H-Gly- ...