Production of tetrahydropyran-4-ones 2-substituted optically active.

They can be prepared tetrahydropyran-4-OLES 2 OR optically active substituted esters using esterases or hydrolases from the corresponding racemic esters or alcohols. This provides a route to the corresponding ketones optically active. MIXTURES RACEMINCAS are preferable in the cis form. Such mixtures can be produced by REACIONAR but-3 JAN 1 OL with an aldehyde in the presence of acid.