Process for the synthesis of (5R)-1,1-dimethylethyl-6-cyano-5-hydroxy-3-oxo-hexanoate

A process for the preparation of the compound of Formula I. ##STR9## which comprises:

• (a) treating a compound of Formula V ##STR10## wherein R is alkyl of from one to ten carbon atoms, allyl, or benzyl and X is a leaving group with a compound of Formula IV
• R.sup.1 --CN IV
• wherein R.sup.1 is a tetraalkylammonium, silver, copper (I), copper (II), an alkali metal or an alkaline earth metal in a solvent at about 0.degree.C. to about the reflux temperature of the solvent to afford a compound of Formula II ##STR11## wherein R is as defined above;
• or optionally treating a compound of Formula VI ##STR12## wherein R is as defined above with a compound of Formula IV in a solvent at about 0.degree. C. to about the reflux temperature of the solvent to afford a compound of Formula II;
• and
• (b) treating a compound of Formula II with a compound of Formula III ##STR13## wherein R.sup.2 is zinc, magnesium or lithium and a solvent at about -80.degree. C. to about room temperature to afford the compound of Formula I.