Footnote 1

For a related preparation of 1-hydroxycyclopentanecarbocylic acid derivatives via a radical pathway, see ref. [7].

 

Footnote 2

Hammer and Undheim have reported a similar approach for the synthesis of cyclic 1-aminocarboxylic acids starting from a chiral glycine equivalent (Schöllkopf bislactim ether) via olefin ring closing metathesis [8,9]. A similar approach to cyclic amino acids via enyne metathesis has been recently reported [10,11].

Footnote 3

The stereochemical outcome of the first alkylation gave also modest diastereoselectivities, this point will be discussed in detail in a forthcoming full paper.

Footnote 4

In this paper, the trans/cis descriptors are describing the relative configuration of the tert-butyl group at C(2) and the largest (according to CIP rules) substituent at C(4).

Footnote 5

The alkylation was performed with pure trans-6. Attempts to deprotonate the cis-6 led mainly to decomposition products.

Footnote 6

For early examples of enyne metathesis catalyzed by a tungsten carbene, see ref. [24]. Ruthenium catalyzed enyne metathesis have been reported, for pioneer examples, see ref. [25-27].

Footnote 7

For syntheses of racemic quinic acid, see ref. [28-30]. For synthesis of (-)-quinic acid, see ref. [31-36]. Quinic acid has been widely applied as chiral building block for the synthesis of natural products, for a review, see ref. [37].