35023-83-7Relevant academic research and scientific papers
Br?nsted Acid Catalysis in Visible-Light-Induced [2+2] Photocycloaddition Reactions of Enone Dithianes
Brenninger, Christoph,P?thig, Alexander,Bach, Thorsten
supporting information, p. 4337 - 4341 (2017/04/04)
1,3-Dithiane-protected enones (enone dithianes) were found to undergo an intramolecular [2+2] photocycloaddition under visible-light irradiation (λ=405 nm) in the presence of a Br?nsted acid (7.5–10 mol %). Key to the success of the reaction is presumably the formation of colored thionium ions, which are intermediates of the catalytic cycle. Cyclobutanes were thus obtained in very good yields (78–90 %). It is also shown that the dithiane moiety can be reductively or oxidatively removed without affecting the photochemically constructed ring skeleton.
Catalytic Enantioselective Nitroso Diels-Alder Reaction
Maji, Biplab,Yamamoto, Hisashi
supporting information, p. 15957 - 15963 (2016/01/09)
The nitroso Diels-Alder (NDA) reaction is an attractive strategy for the synthesis of 3,6-dihydro-1,2-oxazines and 1-amino-4-hydroxy-2-ene derivatives. Herein we report the Cu(I)-DTBM-Segphos catalyzed asymmetric intermolecular NDA reaction of variously substituted cyclic 1,3-dienes using highly reactive nitroso compounds derived from pyrimidine and pyridazine derivatives. In most of the cases studied, the cycloadducts were obtained in high yields (up to 99%) with very high regio-, diastereo-, and enantioselectivities (up to regioselectivity > 99:1, d.r. > 99:1, and >99% ee). As an application of this methodology, formal syntheses of conduramine A-1 and narciclasine were accomplished.
Iron(III) tosylate in the preparation of dimethyl and diethyl acetals from ketones and β-keto enol ethers from cyclic β-diketones
Mansilla, Horacio,Afonso, Maria M.
, p. 2607 - 2618 (2008/12/22)
An efficient method for conversion of ketones to their corresponding dimethyl and diethyl acetals and of cyclic β-diketones into β-keto enol ethers using Fe(OTs)3 as a catalyst is described. Copyright Taylor & Francis Group, LLC.
Synthetic studies towards the phomactins. Concise syntheses of the tricyclic furanochroman and the oxygenated bicyclo[9.3.1]pentadecane ring systems in phomactin A.
Foote, Kevin M,Hayes, Christopher J,John, Matthew P,Pattenden, Gerald
, p. 3917 - 3948 (2007/10/03)
A concise synthesis of the tricyclic furanochroman unit 3 found in the PAF antagonist phomactin A (1) isolated from the marine fungus Phoma sp., is described. In complementary studies, a variety of synthetic routes towards the bicyclo[9.3.1]pentadecane ring system 4 in phomactin A were explored. These studies culminated in a synthesis of the substituted ring system 79 containing all the carbon atoms and all the necessary oxygen centres for elaboration to phomactin A itself.
Biosynthesis of PD 116740: Origins of the carbon, hydrogen, and oxygen atoms and derivation from a 6-deoxybenz[a]anthraquinone
Gould, Steven J.,Cheng, Xing-Chun,Melville, Chris
, p. 1800 - 1804 (2007/10/02)
The benz[a]anthraquinone antibiotic PD 116740 is formed from the regular cyclization of a decaketide intermediate folded in a manner to generate the angular tetracyclic skeleton. The 6-deoxybenz[a]anthraquinone tetrangulol is an intermediate, indicating t
Total Synthesis of rac-Sesquiterpenoid AE 1
Schinzer, Dieter,Fessner, Klaus,Ruppelt, Martin
, p. 139 - 144 (2007/10/02)
rac-Sesquiterpenoid AE 1 (rac-1) can be obtained in an 11-step sequence starting from 5-methylresorcinol (2).The key compound 9 is synthesized by the use of a diastereoselective dienone cyclization with the allylic silane 8.Subsequent transformation of 9 leads to rac-1. Key Words: Sesquiterpenoid AE 1 / Dienone cyclization / Allylsilane
Intramolecular Additions of Allylsilanes to Conjugated Dienones. Direct Stereoselective Syntheses of (+/-)-Neolemnanyl Acetate and (+/-)-Neolemnane
Majetich, George,Lowery, Derric,Khetani, Vikram,Song, Jee-Seop,Hull, Kenneth,Ringold, Clay
, p. 3988 - 4001 (2007/10/02)
The total synthesis of the marine sesquiterpenes neolemnanyl acetate (1) and neolemnane (2) is reported.An intramolecular allylsilane addition to a conjugated dienone is used to assemble the basic 6,8-fused skeleton.Functionalization of the cyclooctane ri
A NEW ROUTE FOR THE EFFICIENT SYNTHESIS OF (+/-)OCHROMYCINONE, A NATURALLY OCCURING BENZANTHRAQUINONE.
Guingant, Andre,Barreto, Marie Manuel
, p. 3107 - 3110 (2007/10/02)
The Lewis acid-catalyzed cycloaddition of juglone 2 with dienes 3 led to the title compound.
Cytochalasin Support Studies. The C14-C19 Subunit of Cytochalasin C. Intramolecular 2 + 2 Photochemical Cycloaddition of Vinyl Sulfones
Musser, Arlene K.,Fuchs, P. L.
, p. 3121 - 3131 (2007/10/02)
An intramolecular 2? + 2? photochemical cycloaddition between a six-membered ring vinyl sulfone and a five-membered ring vinylogous ester is described.The process occurs with moderate regiospecificity, the direction being controlled by a cis-acetonide moiety on the six-membered ring.Attempts to fragment the β-alkoxy sulfone adduct to trigger a DeMayo ring expansion were unsuccessful.
