and 2β-Substituted analogs of 14-epi-previtamin D3 were synthesized and isolated after thermal isomerization of 14-epi-vitamin D3triene at 80 °C. The VDR binding affinity and transactivation activity of osteocalcin promoter in HOS cells were tested, and the 2α-methyl-substituted analog was found to have greater genomic activity than 14-epi-previtamin D3. We found that modification at the C2 position
14-表位-维生素D 3三烯在80°C下热异构化后,合成并分离了14-表位-维生素D 3的2α和2β取代类似物。在HOS细胞骨钙蛋白启动子的VDR结合亲和力和反式激活活性进行了测试,并且2α甲基取代的类似物被发现具有更大的基因组活性比14-外延-previtamin d 3。我们发现,在修改的C2位置塞科-steroidal骨架提供了对前维生素d形式的生物基因组活动以及天然维生素d形式有趣的效果。
Asymmetric synthesis of malic acid-type synthons VIA chiral norephedrine-derived oxazolidines
作者:Anna Bernardi、Silvia Cardani、Carlo Scolastico、Roberto Villa
DOI:10.1016/s0040-4020(01)89766-0
日期:1990.1
Polyoxygenated C4 synthons 5-7 are synthesized in enantiomerically pure form starting from ephedrine derived oxazolidines 2,4 and 13. The 1,4-benzylate addition to 2 and 4, the key step in the synthesis of 5 and 6, proceeds cleanly with almost complete diastereoface selection. The key steps in the synthesis of target 7 are the nucleophilic epoxidation of aldehyde 13 and the lithium dimethyl cuprate
Stereoselective additions to carboxylic acid dianions and β-lactone substituted ester enolates
作者:Johann Mulzer、Peter De Lasalle、Alexander Chucholowski、Ursula Blaschek、Gisela Brüntrup、Ibrahim Jibril、Gottfried Huttner
DOI:10.1016/0040-4020(84)80003-4
日期:1984.1
β-unsaturated β-hydroxy-carboxylic acids 2a/b. A diastereo- and enantioselective aldoltype addition of phenylacetic acid dianion to benzaldehyde has been achieved by employing optically active alkoxide amide bases. Finally, highly stereocontrolled additions to the novel β-lactone substituted ester enolates 22 are described.
Lycoperdinoside A and B, New Glycosides from the Slime Mold Enteridium lycoperdon
作者:Tomáš Řezanka、Radmila Dvořáková、Lumír O. Hanuš、Valery M. Dembitsky
DOI:10.1002/ejoc.200300575
日期:2004.3
Two, novel, six-membered lactone glycosides (lycoperdinoside A and B) were isolated from the slimemoldEnteridiumlycoperdon. Their structures, including the absolute configurations of the hydroxy and methyl groups, were determined by means of extensive spectroscopic data such as MS, IR, UV, and 1D and 2D NMR spectra and chemical degradation. The compounds have structures containing a β-L-amiceto
The stereocontrolled total synthesis of spirastrellolide A methyl ester. Expedient construction of the key fragments
作者:Ian Paterson、Edward A. Anderson、Stephen M. Dalby、Jong Ho Lim、Philip Maltas、Olivier Loiseleur、Julien Genovino、Christian Moessner
DOI:10.1039/c2ob25100k
日期:——
architecture, spirastrellolides represent attractive and challenging synthetic targets. A modular strategy for the synthesis of spirastrellolide A methylester, which allowed for the initial stereochemical uncertainties in the assigned structure was adopted, based on the envisaged sequential coupling of a series of suitably functionalised fragments; in this first paper, full details of the synthesis of these