Steroids (covered in Chapter 26) and their derivatives are

Chapter 8, Problem 8.88

(choose chapter or problem)

Steroids (covered in Chapter 26) and their derivatives are among the most widely used therapeutic agents. They are used in birth control, hormone replacement therapy, and the treatment of inflammatory conditions and cancer. New stereoid derivatives are discovered regularly by systematically modifying the structure of known steroids and testing the resulting derivatives for therapeutic properties. As part of a synthetic strategy for preparing a class of promising steroid derivatives, compound 1a was treated with TsCl and pyridine followed by sodium acetate (CH3CO2Na) to give compound 2a (Tetrahedron Lett. 2010, 51, 69486950). OH CH3 CH3 H O R R O 1 1a : R = R = H 1b : R = H; R = D 1c : R = D; R = H O O O O (a) Sodium acetate functions as a base in this instance. Draw the structure of 2a. (b) Deuterium (D) is an isotope of hydrogen, and deuterons will typically behave very much like protons (although small differences in reaction rates are typically observed). If 1b or 1c were treated with TsCl and pyridine, followed by sodium acetate, 2b or 2c would be produced, respectively. Identify which product (2b or 2c) is expected to contain deuterium and justify your choice.