Polylactides (PLAs) are at the forefront of biodegradable polymer research. These poly(α-hydroxy acids) can be prepared by polycondensation of lactic acid or ring-opening polymerization (ROP) of lactide, both routes typically involving metallic promoters. The first part of this review focuses on the recent achievements reported with metal-free systems via organocatalytic (nucleophilic, cationic and bifunctional) as well as enzymatic approaches. The second part of the review concerns the heterocyclic monomers that give access to poly(α-hydroxy acids) such as PLAs. Two complementary approaches will be discussed: substituted 1,4-dioxane-2,5-diones and synthetic equivalents thereof.

The conversion of furfuryl alcohols by the Piancatelli reaction (and its C- and N-variants) provided highly functionalized cyclopentenones (intermolecular) and spirocycles (intramolecular).

The ambiphilic phosphino-borane i-Pr₂P(o-C₆H₄)BMes₂ affords stable versions of key zwitterionic intermediates by reactions with diethyl azodicarboxylate or PhNCO.

1,2,5-ortho esters of D-arabinose were found to be ideally suited building blocks for the stereoselective formation of α and β arabinofuranosidic linkages after nucleophilic opening of the orthoester with oxygen and sulfur nucleophiles; the tetrasaccharidic cap of the lipoarabinomannan of Mycobacterium tuberculosis was then synthesized in a highly convergent manner.