The first total synthesis of chaetocin (1), a potent histone methyltransferase inhibitor, is described in detail. Key reactions were radical bromination for alpha-oxidation of the diketopiperazine ring, and reductive radical coupling for construction of the dimeric core structure. Stereoselective construction of the disulfide bridges was achieved via substitution reaction with H2S. The total synthesis of 1 was accomplished in nine steps starting from known D-amino acid derivatives. Total synthesis of non-natural ent-chaetocin (ent-1) was also achieved via the established synthetic route, starting from.-amino acid derivatives. (C) 2011 Elsevier Ltd. All rights reserved.
The first total synthesis of chaetocin (1), a potent histone methyltransferase inhibitor, is described in detail. Key reactions were radical bromination for alpha-oxidation of the diketopiperazine ring, and reductive radical coupling for construction of the dimeric core structure. Stereoselective construction of the disulfide bridges was achieved via substitution reaction with H2S. The total synthesis of 1 was accomplished in nine steps starting from known D-amino acid derivatives. Total synthesis of non-natural ent-chaetocin (ent-1) was also achieved via the established synthetic route, starting from.-amino acid derivatives. (C) 2011 Elsevier Ltd. All rights reserved.
The first total synthesis of (+)-chaetocin has been accomplished in nine steps starting from known N-Cbz-N-Me-serine using radical alpha-bromination reaction of diketopiperazine 10 and Co(I)-mediated reductive dimerization reaction of 12 as key reactions. The enantiomers show comparable inhibitory activity toward histone methyltransferase (HMT) G9a, but analogues without the sulfur functionality are inactive.