Process for preparing intermediates to 5-HT4 receptor agonist compounds

A compound of formula (I):

• wherein:
• R1 is selected from hydrogen, —OH, and —OP1, wherein P1 is a hydroxy-protecting group;
• R2 is ═O or —NRaRb, wherein Ra and Rb are independently hydrogen or P2, wherein P2 is an amino-protecting group;
• A is selected from —OC(O)—, —S(O)2—, and a covalent bond;
• W is selected from —N(R3)C(O)R4, —N(R5)S(O)2R6, and a moiety of formula (a):
• wherein Z is selected from NC(O)R4, NS(O)2R6, S(O)2, NH, and NP2;
• R3, R4, R5, and R6 are independently C1-3alkyl;
• and
• n is 0 or 1;
• or a salt thereof.