Long-Range Corner Participation by Cyclopropane. 2. Synthesis and Study of 1-Substituted Tricyclo2,4>nonanes

Article abstract of DOI:10.1021/jo00344a005

Acidity studies on tricyclo<3.2.2.0^2,4>nonane-1-carboxylic acid (16-COOH) vs. bicyclo<2.2.2>octane-1-carboxylic acid (17-COOH) show a slight inductive withdrawal by the cyclopropane ring.In spite of this, acetolysis of (tricyclo<3.2.2.0^2,4>non-1-yl)methyl tosylate (16-CH2OTs) vs. (bicyclo<2.2.2>oct-1-yl)methyl tosylate (17-CH2OTs) yields evidence of an anchimeric effect of 18.3 at 25 deg C for cyclopropane assistance in this solvolysis.Product studies of the acetolysis of 16-CH2OTs demonstrate that cyclopropano ring expansion is preferred, and 83percent of the product is acetate 21, whereas ethano bridge migration is unimportant.These results, as well as studies undertaken in a previous paper, are discussed in terms of corner participation by the cyclopropane ring at the 1-carbinyl group via the back lobe at C-2 of the 2,4-bond.