Synlett 2025; 36(01): 55-58
DOI: 10.1055/a-2306-9316
letter

Improved Synthesis of Pseudoproline and DMB Dipeptide Carboxylic Acids

Wyatt C. Powell
,
Kelly Johnson
,
Peyton Tran
,
Ruiheng Jing
,
Maciej A. Walczak
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



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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