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

• because of its high selectivity and excellent tolerance to different functional groups and reaction conditions. Our group has prepared the first ‘clickable’ PLA using 2-hydroxy-4-pentynoic acid (1) as a precursor (Scheme 1) and studied ‘click’ modification of acetylene functionalized PLA [17]. One new