The stereoselective preparation of 1‐hydroxycyclopentanecarboxylic acid derivatives is reported. The key reaction is either a radical cyclization or a radical annulation mediated by the transfer of a phenylseleno group. The radical precursors are easily synthesized by two consecutive enolate alkylations. Excellent stereochemical control for the quaternary C(1) stereogenic center has been achieved.

A particularly flexible general way to synthesize 1-hydroxycycloalkene-1-carboxylic-acid derivatives from 2-(tert-butyl)-2-methyl-1,3-dioxolan-4-one (1), a chiral equivalent of glycolic acid, is reported. The method is based on a double enolate alkylation of the glycolate derivative, followed by ring closing metathesis. A formal synthesis of (À)-quinic acid is reported to demonstrate the potential of this approach.

The stereoselective preparation of 1-hydroxycyclopenta-precursors are easily synthesized by two consecutive enolate alkylations. Excellent stereochemical control for the necarboxylic acid derivatives is reported. The key reaction is either a radical cyclization or a radical annulation mediated quaternary C(1) stereogenic center has been achieved. by the transfer of a phenylseleno group. The radical [a] as a mixture of the four possible diastereomers (5a/5b/ Eur.