110720-14-4

Upstream product

• 77327-04-9 Didemnin A 
• 118171-92-9 Bzl-(S)-Lac-(S)-Pro-OH 
• 110825-32-6 Bzl-(S)-Lac-(S)-Pro-OMe 
• 328-38-1 (R)-leucine 
• 33106-32-0 (S)-2-(benzyloxy)propanoic acid 
• 110720-18-8 H-Me₂Tyr-ONb 
• 110720-41-7 Z-D-MeLeu-Thr(OH)-O-Me₂Tyr-Pro-Leu-Hip-Ist-Boc 
• 110720-42-8 Z-D-MeLeu-Thr(OH)-O-Me₂Tyr-Pro-Leu-Hip-Ist-H 
• 110720-12-2 C₅₇H₈₄N₆O₁₄ 
• 110720-33-7 Z-D-MeLeu-Thr(OTMSe)-O-Me₂Tyr-Pro-Boc 
• 110720-34-8 Z-D-MeLeu-Thr(OTMSe)-O-Me₂Tyr-Pro-H 
• 110720-38-2 Boc-Ist(TBDMS)-Hip-Leu-OTMSe 
• 110720-31-5 Boc-Pro-Me₂Tyr-ONb 
• 110720-39-3 Boc-Ist-Hip-Leu-OH 

Downstream Products

• 77327-05-0 didemnin B 
• 114607-50-0 didemnin B 

Relevant academic research and scientific papers

Efficient total synthesis of didemnins A and B

Didemnins A and B (1 and 2), cytotoxic cyclic peptides from a Caribbean tunicate Trididemnum solidum, have been efficiently prepared by a convergent scheme from two key eastern and western fragments. Efficient routes to derivatives of the constituents of didemnis were explored. Benzyl (2RS,4S)-[O-(tert-butyldimethylsilyl)hydroxyisovaleryl]propionate (Hip derivative) was prepared from 2-hydroxyisovaleric acid by use of C-acylation of Meldrum's acid with diethyl phosphorocyanidate as a key step. Derivatives of (3S,4R,5S)-isostatine (Ist) were prepared from Boc-(R)-alloisoleucine. Methylation of Boc-(R)-Leu-OH and Z-(S)-Tyr-OH respectively afforded the corresponding N-methyl and N,O-dimethyl derivatives. The key eastern fragment, (2RS,4S)-Hip-(S)-Leu-(S)-Pro-OBzl (3), was prepared stepwise from (S)-Pro-OBzl, while Boc-(R)-MeLeu-(S)-Thr[Z-(S)-MeTyr(Me)]-(3S,4R,5S)-Ist(TBDMS)-OH (4), the key western fragment for didemnin A (1), was prepared from Ist derivatives. Coupling of 3 with 4 and cyclization, followed by deprotection, afforded didemnin A (1), which was converted to didemnin B (2).