Formation of Cyclopropanol via Intramolecular P-Hydrogen Abstraction

Nonetheless, there are some examples of cyclopropanol formation by straightforward P-hydrogen abstraction. The Diels-Alder adduct 100 prepared from o-quino- 

Formation of Cyclopropane Ring via Intramolecular 7-Hydrogen Abstraction 

The first photochemical [3 + 2] cycloadditions of arenes with aikenes were reported by two groups in 1966 [76, 77]. This is one of three types of cycloaddition reaction ortho, meta, and para) of arenes with aikenes, and is referred to as the meta-cydoaddition reaction. There are many combinations of arenes and aikenes and, indeed, a large number of reports and reviews have been made on the regiochemistry and stereochemistry [78]. Because this reaction can be used easily to construct a tricyclo[3.3.0.02,8]oct-3-ene framework, the organic syntheses of many natural compounds using this method have been attempted [79], in which the photochemical [3 + 2] cydoaddition plays a key role. 

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