An economical and safe procedure to synthesize 2-hydroxy-4-pentynoic acid: A precursor towards ‘clickable’ biodegradable polylactide

• Quanxuan Zhang,
• Hong Ren and
• Gregory L. Baker

Beilstein J. Org. Chem. 2014, 10, 1365–1371, doi:10.3762/bjoc.10.139

• Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA 10.3762/bjoc.10.139 Abstract 2-Hydroxy-4-pentynoic acid (1) is a key intermediate towards ‘clickable’ polylactide which allows for efficient introduction of a broad range of pendant functional groups

• hydroxylation of propargylic malonate 5 without work-up of any intermediate. Keywords: alkylation; ‘click’ chemistry; ‘clickable’ polylactide; decomposition; diethyl 2-acetamidomalonate; 2-hydroxy-4-pentynoic acid; one-pot; optimization; propargyl bromide; propargyl tosylate; safe and economical; Introduction

• remove any possible oxidants (like HNO2 and HNO3) to prevent decomposition of product 1 while drying under vacuum. Overall, this procedure represents a practical and economical approach to conveniently synthesize precursor 1 for preparation of ‘clickable’ polylactide biomaterials. Experimental General