Processes and intermediates for preparing MCL1 inhibitors

A method comprising preparing a compound of formula 13-D or a salt thereof

• by reacting a compound of formula 13-C:
• with a corresponding compound of formula 6-L
• or a salt thereof, to provide the compound of formula 13-D or the salt thereof, wherein RP is selected from —C(═O)—C1-6alkyl, —C(═O)-phenyl, —C(═O)—O—C1-6alkyl, —C(═O)—O—C1-6alkyl-phenyl, and —C(═O)—O—phenyl;
• wherein R2 is H, R3 is methyl, Ry is H, and R6 is Cl, and
• wherein Rn is independently C1-6alkyl, or the two Rn moieties collectively form a C2-4alkyl bridge, wherein said bridge is optionally substituted by one to four C1-3alkyl and phenyl.