Control of Five Contiguous Stereogenic Centers in an Organocatalytic Kinetic Resolution via Michael/Acetalization Sequence: Synthesis of Fully Substituted Tetrahydropyranols

Abstract

An organocatalytic kinetic resolution of racemic secondary nitroallylic alcohols via Michael/acetalization sequence to give fully substituted tetrahydropyranols is described. The process affords the products with high to excellent stereoselectivities (up to 19.9:1.5:1 dr and 98% ee). The highly enantioenriched, less reactive (<i>S</i>)-nitroallylic alcohols <b>3</b> were isolated with good to high chemical yields (30–44%). The synthetic application of the resolved substrate is shown toward the synthesis of enantioenriched (+)-(2<i>S</i>,3<i>R</i>)-3-amino-2-hydroxy-4-phenylbutyric acid