Asymmetric ring-expanding allylation

A very useful extension of the de Mayo reaction has been recently introduced by Blechert et al. (Scheme 6.26) [78]. The retro-aldol fragmentation was combined with an intramolecular enantioselective allylation (asymmetric ring-expanding allylation) catalyzed by a chiral Pd complex. Bicycloheptane 68, for example, was accessible by intermolecular [2 + 2]-photocycloaddition of cyclopentenone 67 with allene. Further transformation in the presence of Pd2(dba)3 (dba = dibenzylideneacetone) and the chiral oxazoline ligand 69 (tBu-phox) resulted in the enantioselective formation of cycloheptadione 70. 

Schulz, S.R. and Blechert, S. (2007) Palladium-catalyzed synthesis of substituted cydoheptane-l,4-diones by an asymmetric ring expanding allylation (AREA). Angewandte Chemie,... 

Scheme 12.45 Asymmetric decarboxylative ring-expanding allylation reaction [108].

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