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Studies on Amino Acids and Peptides, 9. 5‐Thioxoproline and 5‐Thioxoproline Esters – Synthesis and Crystal Structures
Author(s) -
Andersen Torben P.,
Rasmussen Preben B.,
Thomsen Ib,
Lawesson SvenOlov,
Jθrgensen Palle,
Lindhardt Peter
Publication year - 1986
Publication title -
liebigs annalen der chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0170-2041
DOI - 10.1002/jlac.198619860206
Subject(s) - chemistry , disulfide bond , hydrogen bond , amino acid , group (periodic table) , crystal structure , stereochemistry , medicinal chemistry , organic chemistry , molecule , biochemistry
5‐Thioxoproline ( 2a ) is synthesized from 5‐oxoproline ( 1a ) at room temperature with 2,4‐bis(4‐methoxyphenyl)‐1,3,2,4‐dithiadiphosphetane 2,4‐disulfide ( 3 ) in DME. The carboxy group requires no protection because of the mild reaction conditions. 5‐Thioxoproline esters are synthesized either by thionation of the corresponding 5‐oxoproline esters with 3 or by esterification of 2a . Compounds 2a and 5‐thioxoproline methyl ester ( 2b ) both crystallize in the space group P 2 1 2 1 2 1 with Z = 8. Bond lengths and angles in the compounds are compared, and the small differences explained by differences in hydrogen bond pattern.