Asymmetric synthesis of peptides

A process for the production of a compound of formula (Ic):

• comprising reaction of a compound of formula (VII)
• with a compound of formula (III)
• HY—R7 (III)
• wherein X is O, S, or NR8, where R8 is C1-16 alkyl, C6-12 aryl or hydrogen;
• Y is O, S or NH;
• R2 is independently selected from a C1-10 branched or straight chain alkyl group, C5-12 heteroaryl group or C6-12 aryl group, optionally substituted with OR13, SR13, N(R13)2, CO2R13, CON(R13)2, SO2R12, SO3R12, phenyl, imidazolyl, indolyl, hydroxyphenyl or NR13C(═NR13)N(R13)2;
• wherein each R1′ is independently hydrogen or as defined from R1 below;
• R14 is —[CO—C(R1′)(R9)—N(R10)]m—(R11);
• R12 is hydrogen, C1-6 alkyl, C6-12 aryl or N(R13)2, wherein each occurrence of R13 is independently hydrogen, C1-6 alkyl or C6-12 aryl,
• each R9 and R10 is independently hydrogen or a group as defined for R1′;
• or R9 and R10 can together form a 4 to 7 membered ring, optionally substituted with OR13, SR13, N(R13)2, CO2R13, CON(R13)2, C1-10 alkyl or C6-12 aryl,
• wherein said ring can be fully, partially or unsaturated, and wherein the ring may contain one or more heteroatoms selected from O, S or N;
• R11 is hydrogen or an amino protecting group, wherein the amino protecting group is a benzyloxycarbonyl group, a t-butoxycarbonyl group, a 2-(4-biphenylyl)-isopropoxycarbonyl group, a fluorenylmethoxycarbonyl group, a triphenylmethyl group or a 2-nitrophenylsulphenyl group;
• R5 is a C5-12 aryl, C5-12 heteroaryl or C1-8 branched or straight chain alkyl optionally substituted with OR13, SR13, N(R13)2, CO2R13, CON(R13)2, phenyl, imidazolyl, indolyl, hydroxyphenyl or NR13C(═NR13)N(R13)2 or a linker for attachment of formula (VII) to a resin, wherein the linker is OR13, N(R13)2, CO2R13 or SR13, or an alkyl group having 1 to 4 carbons or a C6-12 aryl group, said alkyl and aryl groups being optionally substituted with OR13, N(R13)2, CO2R13 or SR13;
• R6 is hydrogen or
• wherein R5 and X are as defined above;
• R7 is a group
• or is independently selected from a C1-10 branched or straight chain alkyl group or a C6-12 aryl group, optionally substituted with OR13, SR13, N(R13)2, CO2R13, CON(R13)2, SO2R12, SO3R12, phenyl, imidazolyl, indolyl, hydroxyphenyl or NR13C(═NR13)N(R13)2 or wherein R7 and Y together form a 4 to 7 membered ring, optionally substituted with OR13, SR13, N(R13)2, CO2R13, CON(R13)2, SO2R12, SO3R12, phenyl, imidazolyl, indolyl, hydroxyphenyl or NR13C(═NR13)N(R13)2, wherein said ring can be fully, partially or unsaturated, and wherein the ring may contain one or more heteroatoms in addition to Y, selected from O, S or N;
• wherein R1 is independently selected from a C1-10 branched or straight chain alkyl group, C5-12 heteroaryl group or C6-12 aryl group optionally substituted with OR13, SR13, N(R13)2, CO2R13, CON(R13)2, SO2R12, SO3R12, phenyl, imidazolyl, indolyl, hydroxyphenyl or NR13C(═NR13)N(R13)2;
• R4 is a carboxyl protecting group or hydrogen, wherein the carboxyl protecting group is methyl, ethyl, benzyl, t-butyl or phenyl;
• n is 1, 2 or 3, and m is a value selected from 1-100.