Hi, This is not a homework question but something I found within my textbook. I just wanted to understand a solution they gave to the problem. The question is: Predict the product of the following Diels-Alder reaction: The structures of two molecules, a diene (4 carbons long) and a methyl butyrate (methyl butanoate). The answer has the methyl ester and H atom popping out of the book. I just wanted to confirm that it would not be wrong if it was drawn with the methyl ester and H atom going into the book would it? I do not think this is an endo substituent in this case.