Process for synthesis of silane dipeptide analogs

A process for preparing a compound of formula (17):

• wherein:
• R1, R2 and R3 are independently selected from the group consisting of H, C1-10 alkyl, substituted C1-10 alkyl, C1-10 alkenyl, substituted C1-10 alkenyl, heteroalkyl, heteroalkenyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, aryl-(C1-3)alkyl, substituted aryl-(C1-3)alkyl, formyl, alkyl-carbonyl, aryl-carbonyl, and heteroaryl-carbonyl;
• R4 and R5 are independently selected from the group consisting of aryl, substituted aryl, heteroaryl and substituted heteroaryl;
• R7 is —S(O)R8, —S(O)2R8, —S(O)2NR9R10, —C(O)R9, —C(O)NR9R10, a protected carboxyl-linked amino acid or a protected carboxyl-linked peptide;
• R6, R9 and R10 are independently selected from the group consisting of H, C1-10 alkyl, substituted C1-10 alkyl, C1-10 alkenyl, substituted C1-10 alkenyl, heteroalkyl, heteroalkenyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, aryl-(C1-3)alkyl, and substituted aryl-(C1-3)alkyl;
• and,
• R8 is C1-10 alkyl, substituted C1-10 alkyl, C1-10 alkenyl, substituted C1-10 alkenyl, heteroalkyl, heteroalkenyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, aryl-(C1-3)alkyl, or substituted aryl-(C1-3)alkyl;
• said process comprising the steps of:
• (a) reacting lithium metal with a compound of formula (11):
• to form a compound of formula (15):
• (b) reacting said compound of formula (15) with a compound of formula (16):
• to form a reaction mixture;
• and,
• (c) neutralizing said reaction mixture to form said compound of formula (17).

A process for preparing a compound of formula (19):

• wherein:
• R11 is C1-10 alkyl, substituted C1-10 alkyl, C1-10 alkenyl, substituted C1-10 alkenyl, heteroalkyl, heteroalkenyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, aryl-(C1-3)alkyl, substituted aryl-(C1-3)alkyl, formyl, alkyl-carbonyl, aryl-carbonyl, or heteroaryl-carbonyl;
• and,
• R4 and R5 are independently selected from the group consisting of aryl, substituted aryl, heteroaryl and substituted heteroaryl;
• said process comprising the step of reacting lithium metal with a compound of formula (18):
• wherein:
• R8 is C1-10 alkyl, substituted C1-10 alkyl, C1-10 alkenyl, substituted C1-10 alkenyl, heteroalkyl, heteroalkenyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, aryl-(C1-3)alkyl, substituted aryl-(C1-3)alkyl, formyl, alkyl-carbonyl, aryl-carbonyl, or heteroaryl-carbonyl;
• to form a solution of said compound of formula (19).