Intermediates in the preparation of therapeutic fused bicyclic amino acids

A process for the preparation of a compound of formula (IV) or (IVA)

• from a compound of formula (I) or (IA)
• where R represents H or a suitable carboxylic acid protecting group comprising the reaction:
• (i) where R is H, enzymatic hydrolysis of a compound of formula (I) or (IA), where R is a carboxylic acid protecting group;
• or
• (ii) where R is a carboxylic acid protecting group, enzymatic esterification of a compound of formula (I) or (IA) where R is H;
• or
• (iii) chromatographic resolution of the isomers of a compound of formula (I) or (IA);
• or
• (iv) where R is a carboxylic acid protecting group, by enzymatic hydrolysis of a compound of formula (I) or (IA) where R is a carboxylic acid protecting group, followed by re-esterificarion;
• or
• (v) where R is a carboxylic acid protecting group, by removal of the undesired stereoisomer of a compound of formula (I) or (IA) where R is a carboxylic acid protecting group by enzymatic hydrolysis.