Typically, one semester of organic + one semester of biochemistry requires that your school teach it's organic course in a particular (and atypical) fashion that covers all of the relevant reactivity for biochemistry in the first semester.
In a typical organic course, SNAc reactions and most other carbonyl reactivity are covered in the second semester, along with enolate chemistry. Both of which are pretty important to understanding biological reactions.
So the issue isn't finding a biochemistry course that only requires 1 semester of OChem, it's having the correct background in OChem, which depends on your schools curriculum.