Generation of a shorter pulse based on trigger (similar to 555 as monostable)
If I understand your application correctly you can use an edge-triggered monostable multivibrator, for example 74LVC1G123.

As shown in the TI datasheet, figure 2, it is possible to have an output pulse shorter than the input pulse:



If the timing jitter (delay from the input to output) isn't too critical, you could also consider using a tiny microcontroller.