Enantioenriched bifunctional crotylsilanes for the asymmetric synthesis of orthogonally protected 2-methyl-1,3-diols.

Enantiomerically pure α-substituted crotylsilane reagents I and ent-I undergo asymmetric aldehyde crotylation followed by Ir(I)-catalyzed diastereoselective allylic etherification to give a variety of orthogonally protected 2-methyl-1,3-diols at the synthetically useful level of yields and stereoselectivity. The reagents are air-stable and bifunctional so that they can be used in these reactions sequentially without recourse to functional group adjustments.