By -Oxy-Cope

Scheme 7 Shift of unfavorable equilibria by oxy-Cope rearrangement...

Still larger rings may be constructed by this general strategy equation (96) shows the formation of i bicyclo[5.4.0]undecane by oxy-Cope rearrangement of a vinylbicyclo[3.2.2]nonane. ... 

Paquette, L. A, Stereocontrolled synthesis of complex cyclic ketones by oxy-Cope rearrangement. Angew. Chem. 1990, 102, 642-660. 

The product formation can be rationalized by a fragmentation-recombination pathway followed by oxy-Cope rearrangements, as depicted below. 

The oxidation of 2-aUyl-l-naphthols leads to 4-allyl-1,2-naphthoquinones (4 examples, 65-73%) as a result of hydroxylation followed by oxy-Cope rearrangement. ... 

Bicyclic bridgehead olefins with a carbonyl group in the largest bridge can be constructed by oxy-Cope rearrangement of 3-hydroxy-l,5-dienes of types (15) and (16). Considerable interest has been shown in the strained bicyclic enone (17) and several independent syntheses have been reported. ... 

The face selective enone allylation followed by oxy-Cope rearrangement (1 — 2), a highlight of the approach presented here, will have many applications in target-directed synthesis. 

Oxy-Cope rearrangements (95, 98, 99) have been extensively used in natural product synthesis to generate l-oxo-hexa-l,5-diene systems which are then elaborated to introduce the functionality presented in the selected targets. Wender and his coworkers have utilized this methodology in a key step in the synthesis of reserpine (36, 37). They envisioned that the DE-ring precursor 128 could arise from the hydroisoquinoline 129 which could be generated by oxy-Cope rearrangement of isoquinuclidene 130 (Scheme 3.20). This key intermediate, in turn, could be prepared by Diels-Alder reaction of dihydropyridine 131 with an appropriately substituted dienophile 132. 

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