Clearances have a lot to do with the available space as well as your personal size and comfort range.
In a set up like the above you would want to allow 42" to be comfortable. This does not mean that as a cook you would want to have someone passing by you when you are at the stove - if that is what you have to expect then you would want to have 48" of clearance. Having said all that - in a small kitchen, and with only a cooktop in this location, and the oven someplace else, a 36" distance might be acceptable - but that is really an individual decision.

Thanks for the helpful information.