how can i multiply blocks of a block matrix by a non block-matrix, block to elements?

i want multiply blocks of a block matrix by a non block matrix as size of the block matrix is same under blocks, with size non block matrix under elements. for example :

     1     0     1     0                         2   0   3   0 
     0     1     0     1                         0   2   0   3
     1     0     1     0         2     3         4   0   5   0  
                          *      4     5      =  0   4   0   5     
     0     1     0     1