RI 2024 Introduction to Organic Chemistry Self-Check Answers

6 1. 1. Molecular formula (MF) of X: C 12H10N2O2, and MF of Z: C 6H5NO. X and Z have the same empirical formula. 2. MF of Y is also C 12H10N2O2, i.e. same as X, so it is a constitutional isomer of X. 3. MF of Y is double the MF of Z. Answer: Options 1, 2 and 3 are correct 2. (a) 3-chloropent-1-ene (b) 5,6-dihydroxyheptan-3-one (c) 2-ethyl-1,1-dimethylcyclobutane 3. D 4. Spironolactone has a total of 7 chiral carbons. Hence it forms a total of 2 7 stereoisomers. (Ans: D) 5. Methoprene has one chiral carbon and two C=C bonds which have restricted rotation. Thus it forms a total of 2 3 = 8 stereoisomers. (Ans: C) Teacher’s note: One of the 2 pairs of stereoisomers formed from restricted rotation about C=C bonds should be classified as E/Z isomers and not cis-trans isomers; you can expand the discussion to E/Z isomers if you wish to. Suggested Solutions to Self-Check Questions * C CH 3 CH 3 CH 2 CH 2 CH 2 CH CH 2 OCH 3 CH 3 C H C H C CH 3 C H C O O CH CH 3 CH 3 * * * * * * *