Intramolecular Oxidative Coupling of Aromatic Compounds. VII. A Convenient Synthesis of (±)-Deoxyschizandrin

1994 ◽  
Vol 47 (8) ◽  
pp. 1579 ◽  
Author(s):  
AR Carroll ◽  
RW Read ◽  
WC Taylor
Keyword(s):  
Aromatic Compounds ◽  
Oxidative Coupling ◽  
Claisen Rearrangement ◽  
Oxidative Cleavage ◽  
Reductive Coupling ◽  
Convenient Synthesis

A convenient synthesis of (�)-deoxyschizandrin was achieved through the key step of reductive coupling of the bisacetonylbiphenyl (3). The latter compound was synthesized by oxidative cleavage of the bis olefin (5) formed by Claisen rearrangement of the bismethallyl ether of 2,2′,4,4′-tetramethoxybiphenyl-3,3′-diol. The synthesis of 2,2′,4,4′-tetramethoxy-6,6′-di(prop 1-enyl)biphenyl-3,3′-diol (2) is also described. The diphenolic oxidation of (2) did not lead to products with β,β′ carbons linked.

Intramolecular Oxidative Coupling of Aromatic Compounds. VI. An Efficient Synthesis of Some Dibenzocyclooctene Lignans

1994 ◽  
Vol 47 (5) ◽  
pp. 937 ◽  
Author(s):  
AR Carroll ◽  
WC Taylor
Keyword(s):  
Trans Isomer ◽  
Trifluoroacetic Acid ◽  
Aromatic Compounds ◽  
Oxidative Coupling ◽  
Good Yield ◽  
Reductive Coupling ◽  
Efficient Synthesis

The 1,4-diaryl-2,3-dimethylbutanes (4) and (5) were readily prepared by reductive coupling of an arylacetone precursor followed by hydrogenation. Intramolecular oxidative coupling (dichlorodicyanobenzoquinone/trifluoroacetic acid) gave dibenzocyclooctene derivatives in good yield. (�)-Deoxyschizandrin and the corresponding trans isomer, existing in two distinct conformations, were prepared.

C-O Ring Containing Natural Products: Paeonilactone B (Taylor), Deoxymonate B (de la Pradilla), Sanguiin H-5 (Spring), Solandelactone A (White), Spirastrellolide A (Paterson)

2011 ◽  
Author(s):  
Douglass Taber
Keyword(s):  
Oxidative Coupling ◽  
Claisen Rearrangement ◽  
Cyclic Carbonate ◽  
Membered Ring ◽  
State University ◽  
Enantiomerically Pure ◽  
University Of Cambridge ◽  
Spirastrellolide A ◽  
The University ◽  
Oregon State University

Richard J. K. Taylor of the University of York has developed (Angew. Chem. Int. Ed. 2008, 47, 1935) the diasteroselective intramolecular Michael cyclization of phosphonates such as 2. Quenching of the cyclized product with paraformaldehyde delivered ( + )-Paeonilactone B 3. Roberto Fernández de la Pradilla of the CSIC, Madrid established (Tetrahedron Lett. 2008, 49, 4167) the diastereoselective intramolecular hetero Michael addition of alcohols to enantiomerically-pure acyclic sulfoxides such as 4 to give the allylic sulfoxide 5. Mislow-Evans rearrangement converted 5 into 6, the enantiomerically-pure core of Ethyl Deoxymonate B 7. The ellagitannins, represented by 10, are single atropisomers around the biphenyl linkage. David R. Spring of the University of Cambridge found (Organic Lett. 2008, 10, 2593) that the chiral constraint of the carbohydrate backbone of 9 directed the absolute sense of the oxidative coupling of the mixed cuprate derived from 9, leading to Sanguiin H-5 10 with high diastereomeric control. A key challenge in the synthesis of the solandelactones, exemplified by 14, is the stereocontrolled construction of the unsaturated eight-membered ring lactone. James D. White of Oregon State University found (J. Org. Chem. 2008, 73, 4139) an elegant solution to this problem, by exposure of the cyclic carbonate 11 to the Petasis reagent, to give 12. Subsequent Claisen rearrangement delivered the eight-membered ring lactone, at the same time installing the ring alkene of Solandelactone E 14. AD-mix usually proceeds with only modest enantiocontrol with terminal alkenes. None the less, Ian Paterson, also of the University of Cambridge, observed (Angew. Chem. Int. Ed. 2008, 47, 3016, Angew. Chem. Int. Ed. 2008, 47, 3021) that bis-dihydroxylation of the diene 17 proceeded to give, after acid-mediated cyclization, the bis-spiro ketal core 18 of Spirastrellolide A Methyl Ester 19 with high diastereocontrol.

scholarly journals Convenient Synthesis of 6,7,12,13-Tetrahydro-5H-Cyclohepta[2,1-b:3,4-b’]diindole Derivatives Mediated by Hypervalent Iodine (III) Reagent

Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 960 ◽  
Author(s):  
Lei Peng ◽  
Xiaofei Zhang ◽  
Chunhao Yang
Keyword(s):  
Oxidative Coupling ◽  
Biological Activities ◽  
Condensation Reaction ◽  
Large Family ◽  
Membered Ring ◽  
Hypervalent Iodine ◽  
Fischer Indole Synthesis ◽  
Convenient Synthesis ◽  
First Time ◽  
Indole Synthesis

Bisindolyl alkaloids represent a large family of natural and synthetic products that display various biological activities. Among the bisindole compounds, 6,7,12,13-tetrahydro-5H-cyclohepta[2,1-b:3,4-b’]diindoles have received little attention. Only two methods have been developed for the construction of the 6,7,12,13-tetrahydro-5H-cyclohepta[2,1-b:3,4-b’]diindole scaffold thus far, including the classical Fischer indole synthesis conducted by reacting indole-fused cycloheptanone and hydrazines, and the condensation reaction to build the seven-membered ring. Here, we report for the first time a new route to synthesize 6,7,12,13-tetrahydro-5H-cyclohepta[2,1-b:3,4-b’]diindoles through intramolecular oxidative coupling of 1,3-di(1H-indol-3-yl)propanes in the presence of PIFA, DDQ and TMSCl with moderate to excellent yields.

scholarly journals Alkoxide-induced ring opening of bicyclic 2-vinylcyclobutanones: A convenient synthesis of 2-vinyl-substituted 3-cycloalkene-1-carboxylic acid esters

2012 ◽  
Vol 8 ◽  
pp. 650-657 ◽  
Author(s):  
Xiufang Ji ◽  
Zhiming Li ◽  
Quanrui Wang ◽  
Andreas Goeke
Keyword(s):  
Carboxylic Acid ◽  
Ring Opening ◽  
Claisen Rearrangement ◽  
Ring Cleavage ◽  
Unsaturated Ester ◽  
Supplementary Method ◽  
Convenient Synthesis ◽  
High Yields ◽  
Acid Esters

The fused 2-vinyl or 2-phenyl substituted cyclobutanones 4 undergo stereoselective ring openings by the action of alkoxide ions (t-BuO− or MeO−) to produce novel vicinally disubstituted cycloalkene derivatives 5 and 6 in moderate to high yields. The ring cleavage usually occurs with complete regioselectivity. The accessibility of γ,δ-unsaturated ester or acid derivatives makes this transformation a good supplementary method for the well-established Johnson–Claisen rearrangement.

Unusual Regioselectivity in the Reductive Coupling of Alkynes and Allenes by Hydrozirconation and Zinca-Claisen Rearrangement

1997 ◽  
Vol 36 (22) ◽  
pp. 2469-2471 ◽  
Author(s):  
Keisuke Suzuki ◽  
Takahiro Imai ◽  
Shigeo Yamanoi ◽  
Masao Chino ◽  
Takashi Matsumoto
Keyword(s):  
Claisen Rearrangement ◽  
Reductive Coupling
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