14. Which pair of esters is most likely to provide a useful Claisen synthesis (Sec. (Sec. 15. Which is the major product formed in the following reaction? (Sec. 16. What is the major product of the following reaction? (Sec. 17. What is the major product of the following reaction? 18. Which compounds will undergo decarboxylation upon heating? (Sec. (Sec. 19. Which is the major product of the following series of reactions? (Sec. 20. Which is the product of the following series of reactions? 21. Which ester is likely to undergo a Claisen condensation to give this product?