I concur with the comments above, you do not want gas fumes in your house. It can be difficult, particularly if you're range is on an inner wall, but it is very important that gas fumes be vented outside.
When I converted to gas, I had a challenge finding a way to duct the hood, but my solution was to put the range at an angle in the corner, creating space behind to go down and out under the floor. It also provided an opportunity for additional cabinets and shelving.