A Chirality-Returning Sequence for the Synthesis of an Unnatural Isomer of Hirsutellone B

作者：Sugata Hayato; Kato Ryo; Tsubogo Tetsu; Uchiro Hiromi^*

来源：Asian Journal of Organic Chemistry, 2017, 6(5): 609-618.

DOI：10.1002/ajoc.201600610

• atropisomerism
• chirality
• cyclization
• macrocycles
• total synthesis

Herein, we have achieved the synthesis of an unnatural isomer of hirsutelloneB. Previously, we reported the total synthesis of the antituberculosis agent hirsutelloneB. The key step in that synthetic strategy involved the direct construction of a highly strained 13-membered macrocycle by utilizing an intramolecular Ullmann reaction. In this work, we studied the effect of the configuration at the C19 position on the macrocyclization of the 13-membered ring. The central chirality at the C19 position of the cyclization precursor was specifically transferred to give the planar chirality of the enol ether moiety of the 13-membered macrocycle, and the planar chirality was then transferred back to the central chirality at the C19 position of the final product. This chirality-returning sequence enabled the stereoselective construction of the gamma-hydroxylactam of the 13-membered macrocycle of the unnatural isomer of hirsutelloneB.

• 出版日期2017-5