We consider a class of probability measures $μ_{s,r}^α$ which have explicit Cauchy-Stieltjes transforms. This class includes a symmetric beta distribution, a free Poisson law and some beta distributions as special cases. Also, we identify $μ_{s,2}^α$ as a free compound Poisson law with Lévy measure a monotone $α$-stable law. This implies the free infinite divisibility of $μ_{s,2}^α$. Moreover, when symmetric or positive, $μ_{s,2}^α$ has a representation as the free multiplication of a free Poisson law and a monotone $α$-stable law. We also investigate the free infinite divisibility of $μ_{s,r}^α$ for $r\neq2$. Special cases include the beta distributions $B(1-\frac{1}{r},1+\frac{1}{r})$ which are freely infinitely divisible if and only if $1\leq r\leq2$.