Regioselectivity in the ring-opening β-scission of 2-phenyl-1,3-dioxan-2-yl radicals derived from bicyclic benzylidene acetals
作者:Yudong Cai、Hai-Shan Dang、Brian P. Roberts
DOI:10.1039/b208200b
日期:——
2-phenyl-1,3-dioxan-2-yl radicals with fused cyclohexane or cyclopentane rings and there are two modes of cleavage for each radical, to give either a primary or a secondary 3-benzoyloxyalkyl radical. The regioselectivity of β-scission differs markedly depending on whether the ring junction is cis or trans, such that the trans-isomer gives preferentially the primary alkyl radical while the cis-isomer affords
Selectiveoxidations of secondary hydroxyl groups vs. primary ones in 1,n-diols by TS-1/H2O2 catalitic system and by dimethyldioxirane, new reagents with low environmental pollution, are reported.
据报道,TS-1 / H 2 O 2催化体系和二甲基二环氧乙烷是对环境污染低的新试剂,在1,n-二醇中相对于伯羟基选择性地氧化仲羟基。
Heteroaryl compounds useful as inhibitors of E1 activating enzymes
申请人:Claiborne F. Christopher
公开号:US20080051404A1
公开(公告)日:2008-02-28
This invention relates to compounds that inhibit E1 activating enzymes, pharmaceutical compositions comprising the compounds, and methods of using the compounds. The compounds are useful for treating disorders, particularly cell proliferation disorders, including cancers, inflammatory and neurodegenerative disorders; and inflammation associated with infection and cachexia.
NMR and x-ray evidence for the chair conformation of six-membered rings attached diequatorially to five-coordinate phosphorus. Implications for reported transition-state analogs of nucleoside cyclic 3',5'-monophosphate hydrolysis
作者:Yande Huang、Alan E. Sopchik、Atta M. Arif、Wesley G. Bentrude
DOI:10.1021/ja00063a024
日期:1993.5
A series of phosphoranes, 5, 6a, 6b, and 7a, has been prepared and structurally characterized by 1 H NMR spectroscopy and/or X-ray crystallography. In the crystalline state, 5a, 6a, and 6b feature five-coordinate phosphorus bonded in a somewhat distorted, trigonalbipyramidal fashion. The phosphorus-containing six-membered ring is attached to phosphorus diequatoially and is in the chair conformation
已经制备了一系列正膦,5、6a、6b 和 7a,并通过 1 H NMR 光谱和/或 X 射线晶体学对其进行了结构表征。在结晶状态下,5a、6a 和 6b 的特征是五配位磷以稍微扭曲的三角双锥体方式键合。含磷六元环与磷二等位连接,呈椅子构象。1 H NMR 耦合常数表明,对于所有四种磷烷,在溶液中也存在椅子形环,而不是船形或扭曲构象
Reductive Cleavage of <i>tert</i>-Butyldimethylsilyl Ether via Intramolecular Transfer of Hydride
作者:Parthasarathy Saravanan、Suparna Gupta、Arpita DattaGupta、Sonia Gupta、Vinod K. Singh
DOI:10.1080/00397919708004138
日期:1997.8
The cleavage of α-hydroxy tert-butyldimethylsilylether to diol takes place efficiently with LAH. It has been proposed that the reaction proceeds via intramolecular hydride transfer from the alkoxy aluminium hydride. In order to substantiate this, reduction of TBDMS ether with LAH in a variety of substrates was studied.