Di-rt-methane rearrangement

Similarly for the photochemical di-rt-methane rearrangement conical intersection (Fig. 9.7), one has T = 0 under similar conditions ... 

Dienes usually undergo di-rt-methane rearrangement on photochemical excitation (see Section 2.2.2.1). Occasionally, mostly in more rigid molecules, an alternative path involving an intramolecular [2 -I- 2] cycloaddition giving bicyclopentane derivatives is observed (see Houben-Weyl, Vol.4/5a, pp231-238). 

Photochemical fulleroid to methanofiillerene conversion via di-rt-methane rearrangement has been reported by Wudl and coworkers [138]. 

Sadeghpoor, R., Ghandi, M., Najafi, H.M., and Farzaneh, F., The oxa-di-rt-methane rearrangement of P,y-unsaturated ketones induced by the external heavy atom cation effect within a zeohte, /. Chem. Soc., Chem. Commun., 329,1998. 

Singh, V.K., Deota, RT., and Bedekar, A.V., Studies in the synthesis of polycyclopentanoids synthesis, oxa-di-7i-methane rearrangement of annulated bicyclo[2.2.2]octenones and cyclopropane ring cleavage of tetracyclo[6.3.0.0. > 0 > ]undecenones,/. Chem. Soc., Perkin Trans. 1, 903,1992. 

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