Final answer:
The student's question involves the reaction of (R)-2,3-trimethyloxirane with methanol and acid to draw the major product, which is the methanol addition product of the oxirane maintaining the (R)-configuration at the chiral center.
Step-by-step explanation:
The question is about drawing the structural formula of organic chemistry compounds. In the case of the reaction between (R)-2,3-trimethyloxirane and MeOH in the presence of H+, the major product is the methanol addition product of the oxirane. Due to the nature of the reaction, the methanol will add across the oxirane in such a way that the more substituted carbon (the one with more carbon groups attached to it) will be the one that becomes bonded to the oxygen of methanol. This is because the more substituted carbon is better able to stabilize the carbocation intermediate that forms during the reaction. Since the starting material is (R)-2,3-trimethyloxirane, which has a chiral center at the second carbon, the reaction will lead to the formation of a new chiral center where the methanol adds. The major product, therefore, will keep the (R)-configuration at the second carbon, and the location of the addition will depend on the most stable carbocation that can form during the reaction.