Convert bounding box for OL2 to extent for OL3?

I have a database with cities and values for: bb_left, bb_top, bb_right, bb_bottom, locate_x, and locate_y.

Here's an example:

city    -   bb_left -   bb_top  -   bb_right    -   bb_bottom   -   locate_x    -   locate_y
geneve  -   493485  -   124865  -   506522      -   110870      -   499910      -   117983

The data was used for an older application using OpenLayers 2 which supports a bounding box containing just 4 values, however in OpenLayers 3 - I must create an extent with co-ordinate points but I am unsure how to create the co-ords based on the bounding box data.

Is this even possible to convert ?