The invention provides novel inhibitors of IAP that are useful as therapeutic agents for treating malignancies where the compounds have the general formula I: wherein X, Y, A, R<;SUB>;1<;/SUB>;, R<;SUB>;2<;/SUB>;, R<;SUB>;3<;/SUB>;, R<;SUB>;4<;/SUB>;, R<;SUB>;4<;/SUB>;', R<;SUB>;5<;/SUB>;, R<;SUB>;5<;/SUB>;', R<;SUB>;6 <;/SUB>;and R<;SUB>;6<;/SUB>;' are as described herein.