Final answer:
To draw a Newman projection for the major E2 elimination product, place the leaving group and the proton being abstracted antiperiplanar to each other,
typically in a staggered conformation, considering steric hindrance and our understanding that secondary and tertiary substrates favor E2 over primary substrates.
Step-by-step explanation:
The student's question is focused on drawing the Newman projection for the major E2 elimination product. In an E2 mechanism, the most favorable conformation is one in which the leaving group and the hydrogen to be removed are antiperiplanar.
This allows for the most efficient overlap of orbitals facilitating a concerted elimination process. For the Newman projection of the E2 transition state, the base should be shown abstracting a proton that is 180 degrees opposite to the leaving group on the adjacent carbon.
When considering steric hindrance and substrate structure, remember that E2 elimination is more favorable in secondary and tertiary substrates over primary ones because of less competition from S2 mechanisms.
In the Newman projection, bulky groups should be positioned to minimize repulsion with one another, often placing them in the equatorial positions in a staggered conformation relative to the front carbon.
Remember, the key concepts to capture in such a projection are the antiperiplanar orientation of the leaving group and the proton undergoing elimination, as well as the use of a strong base to abstract the proton.
This approach ensures you are capturing the most accurate depiction of the transition state for the major E2 elimination product.