A FACILE METHOD FOR THE SIDE-CHAIN PROTECTION OF ALPHA-METHYL-BETA-3,4-DIHYDROXYPHENYL-L-ALANINE (ALPHA-MEDOPA) FOR SOLID-PHASE PEPTIDE-SYNTHESIS
Hsieh, KH; Demaine, MM
| HERO ID | 1198779 |
|---|---|
| In Press | No |
| Year | 1991 |
| Title | A FACILE METHOD FOR THE SIDE-CHAIN PROTECTION OF ALPHA-METHYL-BETA-3,4-DIHYDROXYPHENYL-L-ALANINE (ALPHA-MEDOPA) FOR SOLID-PHASE PEPTIDE-SYNTHESIS |
| Authors | Hsieh, KH; Demaine, MM |
| Journal | Synthesis |
| Issue | 1 |
| Page Numbers | 59-62 |
| Abstract | Two approaches have been used to prepare N-alpha-tert-butoxycarbonyl-alpha-methy-beta-3,4-dimethoxy-, or dibenzyloxyphenyl-L-alanine, N-alpha-Boc-alpha-MeDopa (R)2, where R is the methyl or benzyl ether. In the first approach, alpha-methyl-beta-3,4-dihydroxyphenyl-L-alanine (alpha-MeDopa) is reacted with di-tert-butyl dicarbonate (Boc2O) in the presence of sodium bicarbonate under anhydrous conditions. The resultant N-protected derivative (Boc-alpha-MeDopa) is methylated with methyl iodide/sodium carbonate, followed by reaction with methyl iodide/tetramethylammonium hydroxide, and saponification with potassium hydroxide in aqueous dioxane to give N-alpha-tert-butoxycarbonyl-alpha-methyl-beta-3,4-dimethoxyphenyl-L-alanine, Boc-alpha-MeDopa(Me)2, in 30 % overall yield. In the second approach, methyl ester of alpha-methyl-beta-3,4-dihydroxyphenyl-L-alanine is prepared by the thionyl chloride/methanol procedure, followed by N-protection with di-tert-butyl dicarbonate/sodium bicarbonate, sidechain protection with benzyl chloride/tetramethylammonium hydroxide, and saponification with sodium hydroxide in aqueous dioxane to give N-alpha-tert-butoxycarbonly-alpha-methyl-beta-3,4-dibenzyloxyphenyl-L-alanine, Boc-alpha-MeDopa(CH2Ph)2, in 46 % overall yield. The latter derivative has been incorporated into angiotensin II under stepwise solid-phase peptide synthesis and solution coupling conditions.< |
| Wosid | WOS:A1991EU00700017 |
| Is Certified Translation | No |
| Dupe Override | No |
| Comments | Source: Web of Science A1991EU00700017 Journal:SYNTHESIS-STUTTGART |
| Is Public | Yes |
| Is Qa | No |