Fragmentation of Alkoxyl Radicals Synthetic Applications

Among the competing principal reactions of alkoxyl radicals, intramolecular hydrogen abstraction and (3-fragmentation have been extensively and successfully used in organic synthesis. This situation is in contrast to the case of carbon-centered radicals in which intramolecular radical addition has been most successfully exploited in synthesis.Some representative examples of the synthetic application are described below. The literature covers up to the beginning of 2002. 

Interestingly, a cascade alkoxyl radical fragmentation-peroxidation-hydrogen abstraction reaction occurs in some cases when a hemiacetal is treated with DIB/I2 under oxygen pressure. This reaction may have interesting applications in synthetic organic chemistry. We have used it in a one-step synthesis of A and A rings of the tetranortriterpene limonene and related compounds (Eq. 19, Scheme 6) [48]. 

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