Reaction scheme: one molecule gives two possibilities

My reaction scheme has 2 possible pathways from a first molecule: I would like to be able to highlight these 2 possibilities using arrows (the command merge seems to be the one to use) but I can't find how to do it.

Here is what I would like to obtain:



I saw examples in the documentation allowing to go from 2 molecules to 1 only but not from 1 to go to 2. I made several attempts with the command merge but unsuccessfully.

From the ChemFig Manual (adapted)



\merge<(c1)(c2)--() can be used to typeset two possible end products (note the <), but the reagents must be givent after the product:



If you really want the arrows, I don't see simple settings with \merge. You can eventually try to draw them in a \subscheme (but if you look closely, you'll see that this is not perfect):