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DOI: 10.1055/a-2306-9316
Improved Synthesis of Pseudoproline and DMB Dipeptide Carboxylic Acids
This work was supported by the National Institutes of Health (R01GM138682).

Abstract
We report a mild method for the preparation of Fmoc-protected dipeptides containing a 2,4-dimethoxybenzyl (DMB) or 2-hydroxy-4-methoxybenzyl (HMB) group or modified as pseudoprolines. To minimize the loss of the Fmoc protection, we optimized the saponification conditions and included a calcium additive that protected the other base-sensitive functionalities and improved the yield of the free acid (36–82%). The reaction requires a combination of CaCl2 and NaOH in a mixture of iPrOH and water at room temperature.
Supporting Information
- Supporting information for this article is available online at https://doi.org/10.1055/a-2306-9316.
- Supporting Information
Publication History
Received: 05 March 2024
Accepted after revision: 15 April 2024
Accepted Manuscript online:
15 April 2024
Article published online:
21 May 2024
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