D2h-bishomohexaprismane ("garudane"). Design of the face-to-face 2 + 2 dimer of norbornadiene
作者:Goverdhan Mehta、S. Padma
DOI:10.1021/ja00257a076
日期:1987.11
Synthese a partir de la reaction de Diels Alder entre la benzoquinone-1,4 et le cyclopentadiene-1,3
Synthese a partir de la reaction de Diels Alder entre la benzoquinone-1,4 et le cyclopentadiene-1,3
Synthesis of sterically rigid macrocycles by the use of pressure-induced repetitive Diels-Alder reactions
作者:Johannes Benkhoff、Roland Boese、Frank-Gerrit Klärner、Arne E. Wigger
DOI:10.1016/0040-4039(94)88165-0
日期:1994.1
Syntheses of the syn-dimethanotetrahydroanthracene and -tetracene derivatives 2a–d and 6a,b are described. Highly stereoselective, pressure-inducedrepetitiveDiels-Alderreactions of these bis-dienophiles with bis-diene 7 lead to the stericallyrigidmacrocycles 10a, 10d, 13a and 14a,b having well defined cavities of different size.
Enantioselective Organocatalytic Desymmetrization of Cyclopentene-1,3-diones through Formal C(sp<sup>2</sup>)–H Amidation
作者:Hao Liang、Xiaotong Zhou、Liyao Zheng、Jun Wang
DOI:10.1021/acs.joc.9b01678
日期:2019.9.6
An enantioselective organocatalytic desymmetrization of 2,2-disubstituted cyclopentene-1,3-diones via a formal C(sp2)–Hamidation is reported. The reaction was carried out with N-methoxy amide as the nitrogen source and commercially available cinchonidine as the catalyst under mild reaction conditions, releasing methanol as the only byproduct. It provides an efficient way to synthesize enantioenriched
the cage propellanes that are transformed into intricate oxa-cycles via ring-rearrangementmetathesis (RRM) and regioselective ring-closing metathesis (RCM) as crucial steps. In addition, we also report the extended pentacycloundecane (PCUD)-based oxa-cages involving the domino cycloetherification followed by olefin metathesis. These oxa-cages involve a domino sequence in which the PCUD core unit remains
Experimental and theoretical investigations into the stereoselectivities of peracid promoted epoxidations of substituted norbornenes and norbornadienes
作者:Alan P Marchand、Bishwajit Ganguly、Rajesh Shukla、Kasireddy Krishnudu、V Satish Kumar、William H Watson、Satish G Bodige
DOI:10.1016/s0040-4020(99)00464-0
日期:1999.7
MCPBA promoted diastereoselective epoxidations of functionalized norbornenes and norbornadienes have been performed, The experimental results thereby obtained have been evaluated by using semiempirical (AMI) quantum chemical modeling. The AMI computational results are consistent with experiment and correctly predict the major product of all MCPBA promoted epoxidations studied herein. Product characterization was assisted via the results of X-ray crystallographic structural analysis in the case of 10a and by comparison of calculated vs. experimental C-13 NMR chemical shifts of the cyclopropyl carbon atoms in 12a and 12b. (C) 1999 Elsevier Science Ltd. All rights reserved.