9 R = Ph 10 R = p-HOC6H4 11 R = p-MeOC6H4 12 R = BuO 13 R = menthylO ... Yb(OTf)3 catalysed allylation of the hydrates of a-keto aldehydes and glyoxylates with allylsilane ... Yang Yang, Mingwen Wang and Dong Wang* Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, PR China ... Yb(OTf)3 catalysed allylation reactions of the hydrates of a-keto aldehydes and glyoxylates with allyltrimethylsilane at room temperature give a-keto and a-ester ...