Abstract
The cycloaddition of isoquinolone and its N-methyl derivative to all the chlorinated ethylenes has been studied. The structures of all of the photoadducts were determined on the basis of X-ray crystallographic analysis as well as nuclear magnetic resonance spectroscopy and it was found that the cyclobutane rings in the adducts took puckered conformation. The details of the two-step closure process via biradical intermediates are discussed and it is concluded that σ-bond rotation prior to spin relaxation in the biradical intermediates takes a primary role in determination of the stereochemical outcome. The interesting fact that more trans products are formed from cis-dichloroethylene and more cis products from trans-dichloroethylene can also be explained in terms of the present proposal.
| Original language | English |
|---|---|
| Pages (from-to) | 3317-3325 |
| Number of pages | 9 |
| Journal | Chemical and Pharmaceutical Bulletin |
| Volume | 38 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - 1990 Jan 1 |
| Externally published | Yes |
Keywords
- X-ray analysis
- biradical intermediate
- conformation
- conformation
- cyclobutane
- halogenated ethylene
- isoquinolone
- photocycloaddition
- puckered
ASJC Scopus subject areas
- Chemistry(all)
- Drug Discovery