Organocatalysis Accompanies Metal-Mediated Synthesis towards 1,2-Diols

Significance

A sequential synthetic procedure for the preparation of 1,2-syn-diols is reported. In this sequence the first step is an organocatalytic secondary amine catalyzed nitrosoaldol reaction of different aldehydes and ketones with 2-nitrosotoluene. The resulting aminoxylated carbonyl compounds are produced in high enantioselectivities. This first stereocenter effectively induces the diastereoselectivity of the subsequent Grignard addition which is carried out without an intermediary workup furnishing the desired products in high overall yields and excellent diastereoselectivity.