Problems and exercisesFacial control by the aldehyde
Exercise 1
Addition of methylmagnesium bromide to 2-phenylpropanal gives mainly one of the two diastereomers of 3-phenylbutan-2-ol. Identify the L, M and S groups and draw the favoured conformation according to the Felkin–Anh model.
Exercise 2
2-(Benzyloxy)propanal gives one diastereomer with a silyl enol ether and TiCl4, and mainly the opposite one with BF3·OEt2. Explain.