“…Although less commonly observed than the 3:2 condensation products, compounds of this type, arising from the aldol condensation of an intermediate pentane-1,5-dione with a third equivalent of ketone, have been isolated with a variety of substituents [32,60,68,69,70,71,72,73]. The relative stereochemistry in 10 , originally proposed on the basis of NMR studies [58], has been crystallographically confirmed [32,69,70,72]. Sequential reaction of the benzaldehyde derivative with two different ketones, Ar 1 COCH 3 and Ar 2 COCH 3 allows the synthesis of compounds 11 via the addition of Ar 2 COCH 3 to the intermediate enone Ar 1 COCH=CHAr.…”