As Vincent explained, there's a good reason why you can't find the adaptor you seek.
And the type of adaptor Xavier2909 mentions above, would not suit your requirement.
You appear to want to be able to connect the 1.9 metre unbalanced / single-ended lead, supplied with your headphones, to a Pentaconn socket.
Even if you could, there would be no advantage to you in doing that.
Presumably a balanced cable is available for your LCD-2.
Alternatively,
because you've got all 4 wires available, you could go balanced more cheaply by replacing your 6.35mm plug with one of these:
If you've never soldered, or dealt with Litz cable before - don't even think about it.
In that case, either buy a ready-made balanced cable, or connect your 6.35mm plug to the 6.35mm socket on the Hip DAC.