The present invention relates to optionally substituted (5- or 7-oxy)-3,4-dihydro-(optionally 4-oxo, 4-thioxo or 4-imino)-1H-pyrrolo[3,4-d]pyrimidin-2(3H,6H)-ones, e.g., Compounds of Formula II-A′ or II-B′ as described herein, processes for their production, their use as pharmaceuticals and pharmaceutical compositions comprising them.
