modification in syntheticchemistry but it remains a formidable challenge to perform on unstrained skeletons. Herein, we describe a radical addition-enabled C–C σ-bond cleavage/reconstruction reaction of unstrained allyl ketones to access various functional indanones bearing a benzylic quaternary center. The synthetic utility of this method has been showcased by the first total synthesis of carexane L, an indanone-based
C-C σ 键断裂和重建是合成化学中结构修饰的重要工具,但在无应变骨架上进行仍然是一个巨大的挑战。在此,我们描述了无张力烯丙基酮的自由基加成C-C σ-键裂解/重建反应,以获得带有苄基四元中心的各种功能性茚满酮。该方法的合成实用性已通过茚满酮天然产物 Carexane L 的首次全合成得到展示。
Synthesis of 9-Substituted Tetrahydrodiazepinopurines: Studies toward the Total Synthesis of Asmarines
作者:Doron Pappo、Shiri Shimony、Yoel Kashman
DOI:10.1021/jo048622g
日期:2005.1.1
A methodology for the preparation of asmarine analogues has been developed. The asmarines are cytotoxic marine alkaloids with a unique tetrahydro[1,4]diazepino[1,2,3-g,h]purine (THDAP) structure. Three cyclization methods were applied for the preparation of the 9,9-disubstituted 10-hydroxy-THDAP system, namely, aminomercurization, iodocyclization, and acid-catalyzed cyclization. The DMPM group of the NOH functionality and cyanoethyl group of the N-9 atom were found to be the most suitable protecting groups. The structures of all compounds were mainly determined from NMR measurements including N-15 chemical shifts obtained from (NH)-N-15 HMBC spectra. The end products are at least about 1 order of magnitude less active than the natural product asmarine B.
Ichikawa, Yoshitaka; Komatsu, Makoto; Takigawa, Tetsuo, Agricultural and Biological Chemistry, 1980, vol. 44, # 11, p. 2709 - 2716
作者:Ichikawa, Yoshitaka、Komatsu, Makoto、Takigawa, Tetsuo、Mori, Kenji、Kramer, K. J.