A stereoselective synthesis of naturally occurring (+)-20 R -dihydrocleavamine by photo-[2+2]-cycloreversion
摘要:
A stereoselective synthesis of (+)-20R-dihydrocleavamine, an alkaloid from Pandaca eusepala and Tabernamontana eglandulose, has been developed using an enantiopure tricyclic ketone accessible from a meso precursor by employing a photo-[2+2]-cycloreversion reaction as the key step. (C) 2001 Elsevier Science Ltd. All rights reserved.
Cyclobutenone as a Highly Reactive Dienophile: Expanding Upon Diels−Alder Paradigms
作者:Xiaohua Li、Samuel J. Danishefsky
DOI:10.1021/ja1056888
日期:2010.8.18
Cyclobutenone was employed as a dienophile in Diels-Alder cycloadditions, provide diverse and complex cycloadducts in good yields. Experimental outcomes indicated cyclobutenone to be more reactive than either cyclopentenone or cyclohexenone. In addition, cycloadducts bearing a strained cyclobutanone moiety were able to undergo regioselective ring expansions to produce corresponding cyclopentanones
Experimental Diels-Alder Reactivities of Cycloalkenones and Cyclic Dienes Explained through Transition-State Distortion Energies
作者:Robert S. Paton、Seonah Kim、Audrey G. Ross、Samuel J. Danishefsky、K. N. Houk
DOI:10.1002/anie.201103998
日期:2011.10.24
Quantum chemical calculations are used to investigate the experimentally measured reactivities of cyclicdienes and cycloalkenones in the Diels–Alder reaction. The interaction energies (red) are nearly constant; differences arise in changes in distortionenergies of both dienophile (blue) and diene (green; see picture, Ea=activation energy; values in kcal mol−1).
量子化学计算用于研究Diels-Alder反应中环二烯和环烯酮的反应活性。相互作用能(红色)几乎恒定;亲二烯体(蓝色)和二烯(绿色;见图片,E a =活化能; kcal mol -1的值)的变形能变化会产生差异。
Preparation of a Promising Cyclobutanone Chiral Building Block: Its Stereochemistry and Utilization
作者:Takahiko Taniguchi、Yasuo Goto、Kunio Ogasawara
DOI:10.1055/s-1997-3270
日期:1997.6
A cyclobutanone possessing a bicyclo[2.2.1]heptene framework endo-tricyclo[4.2.1.02,5]non-7-en-3-one} has been prepared in both enantiomeric forms employing lipase-mediated kinetic resolution as the key step. To determine the absolute configuration, as well as to demonstrate the synthetic potential, both enantiomers of the cyclobutanone obtained have been transformed enantioconvergently into the key intermediate of the sequiterpene (+)-β-santalene and the iridoid monoterpene (-)-boschnialactone.
Stereocontrolled approach to 1,4-disubstituted 1,3-dienes
作者:Barry M. Trost、Stephen A. Godleski、Joachim Ippen
DOI:10.1021/jo00418a001
日期:1978.11
Silver(I) ion catalyzed rearrangements at strained .sigma. bonds. XXVIII. Valence isomerization of homocubanes. Reversible complex formation and kinetic substituent effects operating during silver(I)-induced bond reorganization
作者:Leo A. Paquette、John S. Ward、Roger A. Boggs、William B. Farnham