I know there are adapters to convert USB-C to Dual-Displayport but does this work the other way around? I have not found anything in this regard.
It won't work using one of these adapters because they're not bidirectional.
This will:
Monoprice Bidirectional USB Type-C to DisplayPort Cable - 4K@60Hz, Black, 6ft - Monoprice.com
No longer will you be limited by the direction of your cable! This Bidirectional USB-C? to DisplayPort? Cable allows you to connect your legacy DisplayPort devices to your newest USB-C enabled display
www.monoprice.com
Lou