图 1. (a) 嘧啶并 [5,4-g] 蝶啶 N-氧化物 1 (5 XM) 在 MeCN 中的紫外-可见吸收光谱。(b) 1 (5 m M ) 和 DMA (250 m M ) 与 1 (5 m M ) 在 MeCN 中的混合物的差异光谱。(c) 1 (5 m M ) 和 DMA (50 m M ) 在 MeCN 中的 1 (5 m M ) 和 DMA (50 m M ) 溶液用光栅单色仪(JASCO 模型)照射CRM-FA) 与 2-kW Xe 灯和 4-nm 带宽在氩气气氛下持续 2 小时。
Total synthesis of echinocandins. II. Total synthesis of echinocandin D via efficient peptide coupling reactions
作者:Natsuko. Kurokawa、Yasufumi. Ohfune
DOI:10.1021/ja00279a065
日期:1986.9
protected to avoid the y-butyrolactonization as well as pyrrolidine formation. Introduction of the linoleyl moiety onto the amino group (6d 7b) followed by the oxidation of the alcohol gave the aldehyde 7c, which upon protection with the dimethyl acetal moiety gave the acetal 7d (42% from 6d). This was converted to 7e by the following sequence of reactions: (i) 1 N NaOH, (ii) CH2N2, and (iii) tert-butyldimethylsilyl
适当保护以避免γ-丁内酯化以及吡咯烷的形成。将亚油基部分引入氨基(6d 7b),然后将醇氧化得到醛7c,在用二甲基缩醛部分保护后得到缩醛7d(42%来自6d)。通过以下反应顺序将其转化为7e:(i) 1N NaOH,(ii) CH 2 N 2 和(iii)叔丁基二甲基甲硅烷基三氟甲烷~磺酸盐/2,6-碘丁烷;~7e,来自7d的87%;[ . ] * 'D 8。3 O(c 0.7,CHCl3)。至此,我们高效地完成了棘白菌素组成氨基酸的合成。棘白菌素 D (3) 的全合成将在以下论文中进行描述。
Asymmetric syntheses of protected (2S,3S,4S)-3-hydroxy-4-methylproline and 4′-tert-butoxyamido-2′-deoxythymidine
3S)-3-hydroxyproline 1; (iii) (2R,3S)-3-hydroxyprolinol 5, and (iv) 4′-tert-butoxyamido-2′-deoxythymidine 6b. The method features a stepwise regio- and diastereoselective reductive furylation of the protected (3S,4S)-4-methylmalimide 10, (S)-malimide 9, and a chemoselective oxidative transformation of the furyl group to the carboxyl group as the key steps.
Synthesis of proteasome inhibitor 6-deoxy-omuralide and its enantiomer using stereoselective alkylation of substituted proline ester
作者:Feng Li、Volker Jäger
DOI:10.1039/d0ob01053g
日期:——
A potent 20S proteasomeinhibitor, 6-deoxy-omuralide was stereoselectively synthesized in 20 steps with 5.1% overall yield staring from a chiral boron agent and D-glyceraldehyde acetonide. The stereoselective alkylation of the substituted proline ester with 3-iodo-2-methylprop-1-ene served as the key step. The enantiomer of 6-deoxy-omuralide was achieved in 20 steps with 4.6% overall yield by just