- STUDIES ON AMINO ACIDS AND PEPTIDES - VII SYNTHESES OF ASPARTAME AND THIOASPARTAME
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The protected aspartame, 4, has been prepared from the benzyl ester of N-benzyloxycarbonyl-S-aspartic acid, 1, and the methyl S-phenylalanate, 3, using 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide, LR, as a coupling reagent.Another protected aspartame, 7, has been prepared from the tert-butyl ester of 1--succinimide, 6, and methyl S-phenylalanate, 3.Thiations of 4/7 by LR produces a protected thioaspartame, 5/9.Deprotection of 7 and 9 gives aspartame, 8, and the slightly sweet thioaspartame, 10, in high yields.
- Yde, B.,Thomsen, I.,Thorsen, M.,Clausen,K.,Lawesson, S.-O.
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p. 4121 - 4126
(2007/10/02)
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