Materials and Methods Unless otherwise stated, reactions were performed in oven-dried
glassware fitted with rubber septa under a nitrogen atmosphere and Teflon-coated magnetic
stirring bars were used to stir the reaction. Solvents and reagents (liquid) were transferred
via syringe using standard Schlenk techniques. Tetrahydrofuran (THF) and diethyl ether
(Et2O) were distilled over sodium/benzophenone ketyl. Dichloromethane (CH2Cl2), toluene
were distilled over calcium hydride. All other solvents such as CH3CN, MeOH and reagents …

A highly diastereoselective Grignard addition to N-tosyl-l-prolinal has been developed to
deliver a variety of proline-derived vicinal amino alcohols in good to excellent yields with
high diastereoselectivities. A similar selectivity was also obtained by using N-tosyl-d-
prolinal. The methodology has been applied to the synthesis of medicinally important 3-
hydroxy-2-phenylpiperidines.