Methods for hydroxylyation of chemical compounds

A process for preparing a product compound of formula (Ia),

• the process comprising:
• i. contacting a substrate compound of formula (IIa)
• with an engineered polypeptide comprising an amino acid sequence having at least 90% sequence identity to SEQ ID NO:2,
• ii. in the presence of α-ketoglutaric acid at a concentration equimolar or higher than that of the substrate compound concentration, under suitable reaction conditions to prepare a product compound of formula (Ia);
• wherein for the compound of formula (Ia) and the compound of formula (IIa),
• Q is (C1-C5)alkylene;
• L is (C1-C4)alkylene;
• R6 is halo;
• and
• wherein the sum of ring carbon atoms of said Q +L is an integer from 2 to 5;
• with the provisos that
• (i) when the sum of ring carbon atoms of said Q +L is 2, then L is a methylene;
• and
• (ii) when the sum of ring carbon atoms of said Q +L is 3, then L is either a bond or ethylene;
• and
• wherein the engineered polypeptide comprises a mutation of X166T/Q/L.