Read it again. the OP actually wants to connect SCSI to USB.
OP - still the same question. A SCSI drive to a USB port, or a USB drive to a SCSI port? Either one is unlikely to exist.
One of my treasured keepsakes is an internal (for the ribbon cables) 68-pin to 50-pin SCSI adapter that was in one of our servers at work. It did not terminate the other signals, and that machine never really worked until we took that ridiculous piece of sabotage out of it.
Rawr Wyoming, Rar. lol.
Anyways - missed the USB part. I highly doubt you would find such a device....your trying to connect what used to be an expensive connector to a cheap connector.
OP is out of luck!