2495-81-0Relevant articles and documents
Total synthesis of (+)-yatakemycin
Okano, Kentaro,Tokuyama, Hidetoshi,Fukuyama, Tohru
, p. 7136 - 7137 (2007/10/03)
A convergent total synthesis of (+)-yatakemycin was accomplished in a 20-step sequence in an overall yield of 13%. The synthesis features the regioselective ring opening of (S)-epichlorohydrin with 2,6-dibromophenyllithium species, the mild copper-mediated aryl amination utilizing the combination of CuI and CsOAc, and the efficient deprotection of benzyl groups of aryl benzyl ether with BCl3 in the presence of pentamethylbenzene. Copyright
Asymmetric total synthesis of (+)- and ent-(-)-yatakemycin and duocarmycin SA: Evaluation of yatakemycin key partial structures and its unnatural enantiomer
Tichenor, Mark S.,Trzupek, John D.,Kastrinsky, David B.,Shiga, Futoshi,Hwang, Inkyu,Boger, Dale L.
, p. 15683 - 15696 (2007/10/03)
Complementary to studies that provided the first yatakemycin total synthesis resulting in its structure revision and absolute stereochemistry assignment, a second-generation asymmetric total synthesis is disclosed herein. Since the individual yatakemycin subunits are identical to those of duocarmycin SA (alkylation subunit) or CC-1065 (central and right-hand subunits), the studies also provide an improvement in our earlier total synthesis of CC-1065 and, as detailed herein, have been extended to an asymmetric total synthesis of (+)-duocarmycin SA. Further extensions of the studies provided key yatakemycin partial structures and analogues for comparative assessments. This included the definition of the DNA selectivity (adenine central to a five-base-pair AT sequence, e.g., 5′-AAAAA), efficiency, relative rate, and reversibility of ent-(-)-yatakemycin and its comparison with the natural enantiomer (identical selectivity and efficiency), structural characterization of the adenine N3 adduct confirming the nature of the DNA reaction, and comparisons of the cytotoxic activity of the natural product (L1210, IC50 = 5 pM) with those of its unnatural enantiomer (IC50 = 5 pM) and a series of key partial structures including those that probe the role of the C-terminus thiomethyl ester. The only distinguishing features between the enantiomers is that ent-(-)-yatakemycin alkylates DNA at a slower rate (krel = 0.13) and is reversible, whereas (+)-yatakemycin is not. Nonetheless, even ent-(-)-yatakemycin alkylates DNA at a faster rate and with a greater thermodynamic stability than (+)-duocarmycin SA, illustrating the unique characteristics of such "sandwiched" agents.
Total synthesis, structure revision, and absolute configuration of (+)-yatakemycin
Tichenor, Mark S.,Kastrinsky, David B.,Boger, Dale L.
, p. 8396 - 8398 (2007/10/03)
The total synthesis of the reported structure 2 for yatakemycin, an exceptionally potent, naturally occurring antitumor agent disclosed in 2003, and its lack of correlation with the natural product are detailed. On the basis of spectroscopic distinctions
