Wharton reaction fragmentation

Ring opening by intramolecular attack by an electron source located on a /3-carbon is represented by the Wharton reaction (Scheme 62) (8UCS(P1)2363) and the Eschenmoser fragmentation (Scheme 63) (81S276). 

Although both are associated with P. S. Wharton, the Wharton fragmentation is a completely different transformation than the Wharton reaction (also called the Wharton transposition, rearrangement, or reduction). For a review of the Wharton reaction, see Li, J. J. In Name Reactions for Functional Group Transformations, Li, J. J., Ed. Wiley Hoboken, New Jersey, 2007 pp 152-158. 

Similar fragmentations to produce S-cyclodecen-l-ones and 1,6-cyclodecadienes have employed l-tosyloxy-4a-decalols and 5-mesyloxy-l-decalyl boranes as educts. The ringfusing carbon-carbon bond was smoothly cleaved and new n-bonds were thereby formed in the macrocycle (P.S. Wharton, 1965 J.A. Marshall, 1966). The mechanism of these reactions is probably E2, and the positions of the leaving groups determine the stereochemistry of the olefinic product. 

A base-catalyzed Grob-Wharton fragmentation of a hydroxybicyclo[5.4.0]nonyl sulfone 3 yielded a cyclononenone derivative 4.193 The reaction is initiated by lactone cleavage with powdered potassium hydroxide in methanol, whereas sodium methoxide was not successful. 

This reaction type is called a Grob as well as a Wharton fragmentation [1] [2]. 

The great utility of fragmentations, especially those of 1,3-diol monosulfonates, for the construction of functionalized, medium-sized cycloalkenes was developed by Wharton, by applying previous results. In recognition of his important contributions to the chemistry of heterolytic fragmentations of cyclic 1,3-diol derivatives, this reaction type has been referred to in a recent review as the Wharton fragmentation . ... 

Related reactions Eschenmoser-Tanabe fragmentation, Wharton fragmentation ... 

This reaction is related to the Bamford-Stevens Reaction, Grob Fragmentation and Wharton Rearrangement. 

---