Stereochemically controlled syntheses of some bicyclo[n.3.0]alkane-1-carboxylic acids

Abstract

Stereospecific methods of synthesis of some cis- and trans-bicyclo[n.3.0]alkane-1-carboxylic acids are described, specifically 5a, 5b, and 11. The cis ring fusion is insured by use of the Diels–Alder reaction, and the trans ring fusion is fixed by the necessity of a cis attachment of an intermediate five-membered cyclic lactamol to the existing cyclopentane ring in 9.