Concise and direct construction of cis-pyrano[4,3-b]pyran-5-one skeleton from glucal derivatives: synthesis of ent-4-deoxy-2,3-di-epi-dinemasone BC
作者:Xiaochao Xue、Wei Li、Zhaojun Yin、Xiangbao Meng、Zhongjun Li
DOI:10.1016/j.tetlet.2015.07.055
日期:2015.9
(−)-Dinemasones B and C were isolated from a culture of the endophytic fungus Dinemasporium strigosum and had shown attractive antimicrobial activities in vitro. Described herein is the concise synthesis of their analogue, ent-4-deoxy-2,3-di-epi-dinemasone BC, from glucal derivatives, including C-glycoside and 3-deoxy-glucal, and the strategies proceeded in 7 steps in 13% overall yield and in 9 steps
(-)-地孕酮B和C是从内生真菌Dinemasporium strigosum的培养物中分离得到的,并在体外显示出有吸引力的抗菌活性。本文描述了由包括C-糖苷和3-deoxy-glucal在内的葡糖衍生物对它们的类似物ent -4-deoxy-2,3- di - epi - dinemasone BC的简明合成,该策略分7步进行。总产率分别为13%和9个步骤,总产率为17%。
Hydroxylic additives enhance yield and scalability of silicon-directed Nazarov reaction
作者:Shaon Joy、Waka Nakanishi、F.G. West
DOI:10.1016/j.tetlet.2013.07.139
日期:2013.10
As a result of difficulties in scaling up silicon-directedNazarovcyclization for use in the synthesis of taxane natural products, the effect of additives was examined. Hydroxylic additives were found to convey a consistent beneficial effect on the rate, overall yield, and scalability of these reactions. Optimal conditions (1.5 equiv methanol or water with substoichiometric FeCl3), were successfully
Synthesis of the C(18)–C(26) segment of superstolide A
作者:William R. Roush、Larry Hertel、Matthew J. Schnaderbeck、Neal A. Yakelis
DOI:10.1016/s0040-4039(02)00903-6
日期:2002.7
A stereoselective synthesis of the C(20)–C(26) fragment of superstolide A is described.
立体选择性合成的超类化合物A的C(20)–C(26)片段进行了描述。
Stereoselective Nazarov Cyclizations of Bridged Bicyclic Dienones
作者:Robert D. Mazzola、Timothy D. White、Heidi R. Vollmer-Snarr、F. G. West
DOI:10.1021/ol051169q
日期:2005.6.1
Bridged bicyclic dienones underwent silyl-directed Nazarov cyclization with generally very high diastereoselectivity. In most cases, a strong preference for cyclization to the product with an exo-disposed cyclopentenone was seen. However, the presence of additional unsaturation in the three-carbon bridge of a bicyclo[3.2.1]octadiene system caused complete reversal in selectivity with exclusive formation of the endocyclopentenone. The observed selectivities are believed to result from a combination of steric and electronic effects.
Yakelis, Neal A.; Roush, William R., Journal of Organic Chemistry, 2003, vol. 68, # 10, p. 3838 - 3843