The nomenclature rules for organic compounds set by the International Union of Pure and Applied Chemistry (IUPAC) committee (http://www.iupac.org/) do offer flexibility in some areas especially in cases where old publications have old terms. Below are some examples.
The answers for the structures, as based on the IUPAC nomenclature rules, are listed below. Some links are also included.
- A and B – for retained replacements see http://goldbook.iupac.org/H02924.html and http://goldbook.iupac.org/S06106.html
- A and B – for locants position see http://goldbook.iupac.org/HT07048.html
- A and B – for Hantzsch-Widman stems see http://goldbook.iupac.org/I03004.html and http://goldbook.iupac.org/P04567.html and http://onlinelibrary.wiley.com/doi/10.1002/ange.19680801212/abstract
- A and B – language
Please note that the image was changed for the problem described in Box#2. It listed the incorrect names for the corresponding structure.
Thank you TLP for your comment.