One to Eight

Here are some 'funny factorisations'. Complete the following expressions so that each one gives a four digit number as the product of two two digit numbers and uses the digits $2$ to $9$ once and only once.

** $\times$ ** $= 4876$
** $\times$ ** $= 5394$

Now do the same with the digits $1$ to $8$ to complete the following expressions.

** $\times$ ** $= 1368$
$5$* $\times$ $6$* $=$ ****
$52$ $\times$ ** $=$ ****

Is there more than one solution?