The synthesis and reactivity of [N(8)-C(3')]-cyclized bicyclomycin. Evidence of the role of the C(1)-triol group in bicyclomycin-mediated processes
作者:Marco A. Vela、Harold Kohn
DOI:10.1021/jo00045a041
日期:1992.9
The C(1) triol group in the antibiotic, bicyclomycin (1) has been proposed to play an integral role in the bonding of key protein nucleophiles to the distal C(5)-C(5a) terminal double bond in the drug. Evidence in support of this concept has been provided by the comparison of the reactivities of bicyclomycin (1), the [N(8)-C(3')]-cyclized bicyclomycin adduct 3, 2',3'-bicyclomycin acetonide (17), and the acetonide derivative of 3, 18, with sodium ethanethiolate. Significantly, 3 displayed enhanced reactivity versus 1, 17, and 18 in this transformation. The controlling factors for the increased reactivity of 3 have been discerned and the importance of the C(1') hydroxyl group delineated. Key kinetic parameters are reported for the treatment of both 3 and 17 with 2-mercaptopyridine. Structural details are provided for both C(5a) thiolate and amine adducts of 3. The importance of these findings in relation to the mode of action of bicyclomycin are briefly discussed.