Synthesis of functionalized hexahydro-, octahydro-, and decahydro-1H-phenalenes via Diels–Alder reactions of 1-methylene-4a-methoxycarbonyl-1,2,3,4,4a,5,6,7-octahydronaphthalene and related dienes

1993 ◽  
Vol 71 (9) ◽  
pp. 1463-1483 ◽  
Author(s):  
Edward Piers ◽  
Richard W. Friesen ◽  
Paul Kao ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Maleic Anhydride ◽  
Transition State ◽  
Methyl Acrylate ◽  
Diels Alder ◽  
Cycloaddition Reactions ◽  
Methoxycarbonyl Group ◽  
The Face ◽  
Group Reaction ◽  
Bicyclic Dienes

The results of a study of Diels–Alder reactions of the bicyclic dienes 6–8 with a variety of dienophiles are reported. Although 6 and 7 undergo cycloaddition reactions smoothly and efficiently, thermal Diels–Alder reactions of 8 are generally sluggish or, under the conditions investigated, do not proceed at all. Additions of tetracyanoethylene (TCNE) to 6–8 are highly face-selective, with preferential attack of the dienophile on the side of the dienes opposite to the angular methoxycarbonyl group. Reaction of 7 with maleic anhydride (MAN) is completely face-selective and proceeds preferentially via an endo transition state. Diels–Alder reactions of 6 and 7 with methyl acrylate (MAC) and nitroethylene (NE) are entirely regioselective, but the face-selectivities, which vary from ~2:1 to ~3:1, are rather low. The use of this chemistry as a method for the synthesis of functionalized, stereochemically defined, perhydro-1H-phenalenes is demonstrated.

Diastereoselectivity and asymmetric induction in the Diels–Alder reaction of o-quinodimethanes

1986 ◽  
Vol 64 (4) ◽  
pp. 720-725 ◽  
Author(s):  
James L. Charlton
Keyword(s):  
Maleic Anhydride ◽  
Methyl Acrylate ◽  
Dimethyl Fumarate ◽  
Alder Reaction ◽  
Diels Alder ◽  
Asymmetric Induction ◽  
Diels Alder Reaction ◽  
The Absolute ◽  
Alkoxy Groups

The extent of asymmetric induction in the bimolecular Diels–Alder reactions of chiral o-quinodimethanes with dimethyl fumarate, methyl acrylate, and maleic anhydride has been studied. o-Quinodimethanes with chiral α-alkoxy groups were prepared from 1-alkoxy-1,3-dihydrobenzo[c]thiophene-2,2-dioxides 4a–f or 1-alkoxy-3-phenyl-1,3-dihydrobenzo[c]thiophene-2,2-dioxides 4g–h by thermolysis. These alkoxybenzosulfones were prepared from the corresponding hydroxybenzosulfones 8 and 1-phenylethanol, 2-phenyl-1-propanol, 4-phenyl-2-butanol, 1-phenyl-2-propanol, 3,3-dimethyl-2-butanol, or 1-cyclo-hexylethanol. The 1-phenylethoxy substituent yielded the largest asymmetric induction. The absolute configurations of the major cycloadducts of methyl acrylate with the o-quinodimethanes generated from 1-(R- 1-phenylethoxy)- and 1-(S-1-phenylethoxy)-1,3-dihydrobenzo[c]thiophene-2,2-dioxides 4i and 4j have been determined to be 1S,2S-1-(R-1-phenylethoxy)- and 1R,2R-1-(S-1-phenylethoxy)-2-carbomethoxy-1,2,3,4-tetrahydronaphthalene 11i and 11j, respectively. The proposition that a chiral alkoxy substituent can block one face of the o-quinodimethane towards addition of a dienophile is discussed.

Asymmetric induction in Diels–Alder reactions of α-alkoxyorthoquinodimethanes

1989 ◽  
Vol 67 (6) ◽  
pp. 1010-1014 ◽  
Author(s):  
James L. Charlton ◽  
Guy L. Plourde ◽  
Glenn H. Penner
Keyword(s):  
Molecular Orbital ◽  
Geometry Optimization ◽  
Diels Alder ◽  
Asymmetric Induction ◽  
Molecular Orbital Calculations ◽  
Cycloaddition Reactions ◽  
Vinyl Ethers ◽  
The Face ◽  
Face Selectivity ◽  
Alkoxy Groups

It has been shown that dienophiles cycloadd selectively to one face of o-quinodimethanes (o-QDMs) bearing chiral α-alkoxy groups. The face selectivity (diastereoselectivity) increases for the series of chiral groups -OCH(Ph)CH3, -OCH(Ph)CH(CH3)2, and -OCH(Ph)C(CH3)3. A similar effect on the face selectivity of the Diels–Alder reactions of chiral alkoxy vinyl ethers for the same series of chiral groups has been noted previously by others. A mechanism has been proposed to explain the face selectivity in the cycloaddition reactions of the alkoxy o-QDMs. Abinitio molecular orbital calculations with geometry optimization on vinyl 1-phenylethyl ether to determine its lowest energy conformations support the proposed mechanism. The absolute stereochemistries of the o-QDM cycloadducts have been determined to verify the predictions of the model. Keywords: o-quinodimethanes, asymmetric, Diels–Alder, cycloaddition.

Reactions of N-3′-furylbenzamide with some dienophiles

1979 ◽  
Vol 57 (3) ◽  
pp. 314-317 ◽  
Author(s):  
John N. Bridson
Keyword(s):  
Double Bond ◽  
Maleic Anhydride ◽  
Methyl Acrylate ◽  
Diels Alder ◽  
First Case ◽  
Dimethyl Maleate ◽  
Related Compounds ◽  
Alder Adduct

N-3′-Furylbenzamide gives a conventional Diels–Alder adduct with maleic anhydride but with dimethyl maleate and methyl acrylate further reactions take place at the enamide grouping of the initially formed adducts. Compounds have been isolated in which molecules of an alcohol, used as solvent, or the starting furan have added to the double bond of the 1:1 adducts. In the first case unstable alkoxyamides are formed; in the second stable 2:1 adducts result from a novel uncatalysed addition to the double bond of the enamide. The stereochemistry of these and related compounds is discussed.

E,E- and E,Z-α-phenyl-α′-acetoxyorthoquinodimethane: steric and electronic control of cycloaddition reactions

1986 ◽  
Vol 64 (4) ◽  
pp. 793-798 ◽  
Author(s):  
James L. Charlton ◽  
Mian M. Alauddin ◽  
Glenn H. Penner
Keyword(s):  
Maleic Anhydride ◽  
Electronic Properties ◽  
Dimethyl Fumarate ◽  
Diels Alder ◽  
Addition Reactions ◽  
Cycloaddition Reactions ◽  
Electronic Control ◽  
Dimethyl Maleate ◽  
Cis And Trans ◽  
Abinitio Calculations

E,E- and E,Z-α-phenyl-α′-acetoxyorthoquinodimethanes have been prepared from the corresponding cis- and trans-1-acetoxy-3-phenyl-1,3-dihydrobenzo[c]thiophene-2,2-dioxides. The regio- and diastereoselectivity of the addition reactions with dimethyl fumarate, dimethyl maleate, maleic anhydride, and methyl crotonate have been determined. Abinitio calculations have been carried out on orthoquinodimethane and its α-phenyl and α-oxy derivatives. A correlation has been made between the steric and electronic properties of the orthoquinodimethanes and the regio- and diastereoselectivity of their Diels–Alder reactions.

An AM1 calculational study of the Diels–Alder addition of maleic anhydride to C5-substituted pentamethylcyclopentadienes and 2,5-dimethylthiophene oxide. An attempt to ascertain the factors controlling the π-facial selectivities and relative reactivities

1994 ◽  
Vol 72 (12) ◽  
pp. 2493-2505 ◽  
Author(s):  
Nick Henry Werstiuk ◽  
Jiangong Ma
Keyword(s):  
Maleic Anhydride ◽  
Transition State ◽  
Empirical Method ◽  
Diels Alder ◽  
Facial Selectivity ◽  
Semi Empirical

The Diels–Alder reactions of maleic anhydride (1) with a group of C5-substituted cyclopentadienes and 2,5-dimethylthiophene oxide (5) have been studied with the semi-empirical method AM1. We find that the facial selectivities and relative reactivities found experimentally for six dienes (2a–2f) are accurately reproduced at this level of theory. The results of the calculational study provide no concrete support for the proposal that σ–σ* hyperconjugation in the transition state – an interaction between a σ bond at C5 of the cyclopentadiene and the incipient σ bonds anti to it (the Cieplak effect) – is the major source of the syn facial selectivity observed for 2a–2d. In addition, the relative reactivities and facial selectivities are predicted for a number of cyclopentadienes which will be synthesized and studied experimentally.

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