Abstract
Cyclopropylidenecyclobutenes and -cyclobutanes were conveniently prepared using the Petasis titanocene approach. The cyclobutenes were unreactive to singlet oxygen, reacting sluggishly via a photoinitiated free radical autooxidative epoxidation process, to yield the corresponding spiroketones. By contrast, cyclopropylidenecyclobutanes react rapidly with 1O 2, via an 'ene' process, initially generating a cyclopropyl hydroperoxide, which proceeds to products via Hock cleavage. The inertness of cyclopropylidenecyclobutenes to a 1O2 'ene' reaction mode may be attributed to the fact that it would require the formation of the relatively high energy cyclobutadiene moiety.
Original language | English |
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Pages (from-to) | 8153-8162 |
Number of pages | 10 |
Journal | Tetrahedron |
Volume | 59 |
Issue number | 41 |
DOIs | |
State | Published - 6 Oct 2003 |
Keywords
- Autoxidation
- Cyclopropylidenecyclobutanes
- Cyclopropylidenecyclobutenes
- Epoxidation
- Oxygen
- Singlet
- Synthesis