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 onto polymers from a single monomer via convenient 'click' chemistry with organic azides. The incorporation of various pendant functional groups could effectively tailor the physicochemical properties of polylactide. The reported synthesis of 1 started from propargyl bromide and ethyl glyoxylate. However, both of starting materials are expensive and unstable; especially, propargyl bromide is shock-sensitive and subjected to thermal explosive decomposition, which makes the preparation of 1 impractical with high cost and high risk of explosion. Herein, we report a simple, economical and safe synthetic route to prepare 1 using cheap and commercially available diethyl 2-acetamidomalonate (4) and propargyl alcohol. The desired product 1 was obtained via alkylation of malonate 4 with propargyl tosylate followed by a one-pot four-step sequence of hydrolysis, decarboxylation, diazotization and hydroxylation of propargylic malonate 5 without work-up of any intermediate.
Original language | English (US) |
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Pages (from-to) | 1365-1371 |
Number of pages | 7 |
Journal | Beilstein Journal of Organic Chemistry |
Volume | 10 |
DOIs | |
State | Published - Jun 17 2014 |
Keywords
- 'Click' chemistry
- 'Clickable' polylactide
- 2-hydroxy-4-pentynoic acid
- Alkylation
- Decomposition
- Diethyl 2-acetamidomalonate
- One-pot
- Optimization
- Propargyl bromide
- Propargyl tosylate
- Safe and economical