The photochemistry of 2,4- and 2,6-cyclo-octadienone

Medium-ring unsaturated ketones have been found to undergo several types of photochemical reactions, including cis-trans isomerization of double bonds, rearrangements, and bridging to bicyclic products. In several instances strained products with trans double bonds undergo further thermal reactions. The present investigation dealt with the photochemistry of 2,4-cyclooctadienone and 2,6-cyclooctadienone. Irradiation of 2,6-cyclooctadienone in inert solvents gave tricyclo [3.2.1.04,7] octan-8-one. This compound was conclusively identified by a cleavage reaction to endo-6-carbomethoxy-bicyclo [3.2.0] heptane. The reduction product of this molecule was identified by comparison of its infrared spectrum to the infrared spectrum of an authentic sample prepared by an unambiguous route. In methanol and furan, however, capture of a reactive intermediate in the photolysis occurred much more rapidly than intramolecular rearrangement. This reactive intermediate was detected by using low temperature photolysis techniques to involve a strained ground state trans intermediate. Irradiation of 2,4-cyclooctadienone produced a dimer resulting from self addition across the c68-double bonds of two molecules of the dienone. The, exact configuration of the dimer at the cyclobutane ring has not yet been determined. Photolysis in methanol and furan also gave products in which the elements of methanol or furan had been added to the dienone. Low temperature photolysis techniques also showed that this molecule was photochemical isomerized to trans-cis-2,4-cyclooctadienone and that subsequent thermal reaction with the nucleophile produced the observed products.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Natural Sciences

Grantor

Rice University

Year dc:date.issued

1969

Author dc:creator

• Solomon, John Steven

Advisor dc:contributor.advisor

• Cantrell, Thomas S.

Statement dc:rights

• Copyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1911/89114

OAI identifier oai:identifier

oai:repository.rice.edu:1911/89114