A method of synthesing a compound of formula III: from a compound of formula VI: which proceeds via a compound of formula VIIa or Vllb: wherein the R 2 group is introduced by coupling a compound of formula XIa, XIb or XIc: (a) (b) (c) wherein: R B represents boronic acid or a boronate; R 2 is selected from a group of: (a) formula Ila: where A is a C 5-7 aryl group, and either: (i) Q 1 is a single bond, and Q 2 is selected from a single bond and -Z-(CH 2) n -, where Z is selected from a single bond, O, S and NH and n is from 1 to 3; or (ii) Q 1 is -CH=CH-, and Q 2 is a single bond; (b) formula IIb: R C1, R C2 and R C3 are independently selected from H and unsubstituted C 1-2 alkyl; (c) formula IIc: L 2 is selected from a single bond and a group of: (a): wherein n is 0 to 3; (b) wherein n is as defined above; (c) wherein n is as defined above; and (d) wherein n is as defined above, E is O, S or NR, D is N, CH, or CR, and F is N, CH, or CR; L 1 is: where X is such that L 1 is an amino-acid residue, a dipeptide residue or a tripeptide residue; Prot is selected from Fmoc (fluorenylmethyloxycarbonyl), Teoc (2-(trimethylsilyl)ethoxycarbonyl) and Boc (t-butoxycarbonyl); R 12 is selected from: (a) C 5-10 aryl group, optionally substituted by one or more substituents selected from the group comprising: halo, nitro, cyano, ether, C 1-7 alkyl, C 3-7 heterocyclyl and bis-oxy-C 1-3 alkylene; (b) C 1-5 saturated aliphatic alkyl; (c) C 3-6 saturated cycloalkyl; (d) wherein each of R 21, R 22 and R 23 are independently selected from H, C 1-3 saturated alkyl, C 2-3 alkenyl, C 2-3 alkynyl and cyclopropyl, where the total number of carbon atoms in the R 12 group is no more than 5; (e) wherein one of R 25a and R 25b is H and the other is selected from: phenyl, which phenyl is optionally substituted by a group selected from halo, methyl, methoxy; pyridyl; and thiophenyl; and (f) where R 24 is selected from: H; C 1-3 saturated alkyl; C 2-3 alkenyl; C 2-3 alkynyl; cyclopropyl; phenyl, which phenyl is optionally substituted by a group selected from halo, methyl, methoxy; pyridyl; and thiophenyl; R 6 and R 9 are independently selected from H, R, OH, OR, SH, SR, NH 2, NHR, NRR', nitro, Me 3 Sn and halo; where R and R' are independently selected from optionally substituted C 1-12 alkyl, C 3-20 heterocyclyl and C 5-20 aryl groups; R 7 is selected from H, R, OH, OR, SH, SR, NH 2, NHR, NHRR', nitro, Me 3 Sn and halo; R" is a C 3-12 alkylene group, which chain may be interrupted by one or more heteroatoms, e.g. O, S, NR N2 (where R N2 is H or C 1-4 alkyl), and/or aromatic rings, e.g. benzene or pyridine; Y and Y' are selected from O, S, or NH; R 6', R 7', R 9' are selected from the same groups as R 6, R 7 and R 9 respectively. (a) (b) (c) wherein: R B represents boronic acid or a boronate; (a) formula Ila: where A is a C 5-7 aryl group, and either: (i) Q 1 is a single bond, and Q 2 is selected from a single bond and -Z-(CH 2) n -, where Z is selected from a single bond, O, S and NH and n is from 1 to 3; or (ii) Q 1 is -CH=CH-, and Q 2 is a single bond; (i) Q 1 is a single bond, and Q 2 is selected from a single bond and -Z-(CH 2) n -, where Z is selected from a single bond, O, S and NH and n is from 1 to 3; or (ii) Q 1 is -CH=CH-, and Q 2 is a single bond; (b) formula IIb: R C1, R C2 and R C3 are independently selected from H and unsubstituted C 1-2 alkyl; (c) formula IIc: (a): wherein n is 0 to 3; (b) wherein n is as defined above; (c) wherein n is as defined above; and (d) wherein n is as defined above, E is O, S or NR, D is N, CH, or CR, and F is N, CH, or CR; (a) C 5-10 aryl group, optionally substituted by one or more substituents selected from the group comprising: halo, nitro, cyano, ether, C 1-7 alkyl, C 3-7 heterocyclyl and bis-oxy-C 1-3 alkylene; (b) C 1-5 saturated aliphatic alkyl; (c) C 3-6 saturated cycloalkyl; (d) wherein each of R 21, R 22 and R 23 are independently selected from H, C 1-3 saturated alkyl, C 2-3 alkenyl, C 2-3 alkynyl and cyclopropyl, where the total number of carbon atoms in the R 12 group is no more than 5; (e) wherein one of R 25a and R 25b is H and the other is selected from: phenyl, which phenyl is optionally substituted by a group selected from halo, methyl, methoxy; pyridyl; and thiophenyl; and (f) where R 24 is selected from: H; C 1-3 saturated alkyl; C 2-3 alkenyl; C 2-3 alkynyl; cyclopropyl; phenyl, which phenyl is optionally substituted by a group selected from halo, methyl, methoxy; pyridyl; and thiophenyl;