1.  From behind the baseline D1 and D2 pass to O1 and O2 respectively.

...on these passes D1 and D2 will then begin their sprint to closeout and defend O3 and O4 respectively.

2.  O1 passes to O3 and O2 passes to O4, these passes create the perfect amount of time for D1 and D2 to closeout and defend.

3.  When O3 and O4 receive the ball, D1 and D2 should be in "D" position having closed out properly.  
O3 and O4 now go 1 on 1 with their D counterparts.

Decide best rotation that works for you.

Points of emphasis:
a.  D players sprinting to O players.
b.  D players closing out properly from a sprint.
c.  D players not over pursuing, keeping good balance.
d.  D players being in good D posture, and positioning as to not allow the O players penetration to the middle.

Notes:
Addition(s) can be made to this drill to set up situation(s) that need to be addressed.  I.E. Limiting the O players to shooting on the catch to work on D checking/blocking out/rebounding.  Use your imagination to create situations your players and collective team need to work on.