α-Oxosulfines: reactions with alkenes and alkynes

1992 ◽  
Vol 70 (3) ◽  
pp. 964-973 ◽  
Author(s):  
Ian W. J. Still ◽  
Donna Kaye T. Wilson
Keyword(s):  
Heterocyclic Compounds ◽  
Diels Alder ◽  
Electrophilic Addition ◽  
Sulfenic Acid ◽  
Tert Butyl ◽  
Yield Formation ◽  
Alder Adduct

Thiochroman-4-one 1,1-dioxide has been successfully converted into 3-sulfinylthiochroman-4-one 1,1-dioxide and the reactions of this α-oxosulfine with a series of alkenes have been carefully investigated. The α-oxosulfine was found to react as a Diels–Alder diene with 2-methylpropene, Z- and E-2-butene, 2-ethyl-1-butene, 1-pentene, Z-2-pentene, and cyclopentene and cyclohexene to produce a new group of heterocyclic compounds, the 2,3-dihydro-5H-1,4-oxathiino[3,2-c][1]benzothiopyrans, in yields ranging from 21 to 42%. In all cases, formation of the Diels–Alder adduct was accompanied by a second type of product, identified as the product of electrophilic addition (EA) of a sulfenium species to the alkene, in lesser yields, ranging from 9 to 18%. When the trapping dienophile used was 3,3-dimethyl-1-butene, only the EA adduct was obtained, in 28% yield. Formation of only the EA type of adduct was also observed in reactions of the α-oxosulfine with 2-butyne (21%) and with the thione 2,2,4,4-tetramethylpentane-3-thione (di-tert-butyl thioketone) (16%). Attempts to prepare the α-oxosulfines corresponding to the following ketones are also described: thiochroman-4-one 1-oxide, isothiochromanone and isothiochromanone 2,2-dioxide, tetrahydrothiophen-3-one 1,1-dioxide, 3,3,5,5-tetramethylcyclohexanone, and 2-indanone. Keywords: Diels–Alder, electrophilic addition, sulfenic acid.

Polar Diels-Alder Reactions Under Microwave Irradiation Employing Different Heterocyclic Compounds as Electrophiles

2019 ◽  
Vol 16 (6) ◽  
pp. 527-543 ◽  
Author(s):  
Pedro M.E. Mancini ◽  
Carla M. Ormachea ◽  
María N. Kneeteman
Keyword(s):  
Organic Synthesis ◽  
Heterocyclic Compounds ◽  
Ionic Conduction ◽  
Theoretical Calculations ◽  
Cycloaddition Reaction ◽  
Diels Alder ◽  
The Other ◽  
Conventional Heating ◽  
Protic Ionic Liquids ◽  
Solvent Free Conditions

During the last twenty years, our research group has been working with aromatic nitrosubstituted compounds acting as electrophiles in Polar Diels-Alder (P-DA) reactions with different dienes of diverse nucleophilicity. In this type of reaction, after the cycloaddition reaction, the nitrated compounds obtained as the [4+2] cycloadducts suffer cis-extrusion with the loss of nitrous acid and a subsequent aromatization. In this form, the reaction results are irreversible. On the other hand, the microwave-assisted controlled heating become a powerful tool in organic synthesis as it makes the reaction mixture undergo heating by a combination of thermal effects, dipolar polarization and ionic conduction. As the Diels-Alder (D-A) reaction is one of the most important process in organic synthesis, the microwave (MW) irradiation was applied instead of conventional heating, and this resulted in better yields and shorter reaction times. Several substituted heterocyclic compounds were used as electrophiles and different dienes as nucleophiles. Two experimental situations are involved: one in the presence of Protic Ionic Liquids (PILs) as solvent and the other under solvent-free conditions. The analysis is based on experimental data and theoretical calculations.

Hetero Diels–Alder reactions of o-thioquinones with cyclic dienes: an efficient synthesis of novel heterocyclic compounds

Tetrahedron ◽  
2001 ◽  
Vol 57 (39) ◽  
pp. 8349-8356 ◽  
Author(s):  
Vijay Nair ◽  
Bini Mathew ◽  
Nigam P Rath ◽  
M Vairamani ◽  
S Prabhakar
Keyword(s):  
Heterocyclic Compounds ◽  
Diels Alder ◽  
Efficient Synthesis ◽  
Cyclic Dienes

scholarly journals Crystal structures and conformations of two Diels–Alder adduct derivatives: 1,8-bis(thiophen-2-yl)-14-oxatetracyclo[6.5.1.02,7.09,13]tetradeca-2(7),3,5-trien-10-one and 1,8-diphenyl-14-oxatetracyclo[6.5.1.02,7.09,13] tetradeca-2,4,6-trien-10-one

2015 ◽  
Vol 71 (2) ◽  
pp. 213-216
Author(s):  
S. Gopinath ◽  
P. Narayanan ◽  
K. Sethusankar ◽  
Meganathan Nandakumar ◽  
Arasambattu K. Mohanakrishnan
Keyword(s):  
Crystal Packing ◽  
Rotation Axis ◽  
Alder Reaction ◽  
Ring System ◽  
Diels Alder ◽  
Compound I ◽  
Diels Alder Reaction ◽  
Phenyl Rings ◽  
Axis Parallel ◽  
Alder Adduct

The title compounds, C21H16O2S2(I) and C25H20O2(II), are products of a tandem `pincer' Diels–Alder reaction consisting of [2 + 2] cycloadditions between benzo[c]furan and cyclopentanone. Each comprises a fused tetracyclic ring system containing two five-membered rings (inenvelopeconformations with the O atom as the flap) and six-membered rings (inboatconformations). In addition, two thiophene rings in (I) and two phenyl rings in (II) are attached to the tetracyclic ring system. The cyclopentanone ring adopts atwistedconformation in (I) and anenvelopeconformation in (II). In (I), the thiophene rings are positionally disordered over two sets of sites, with occupancy ratios of 0.901 (2):0.099 (2) and 0.666 (2):0.334 (2). In (II), the oxygen atom of the cyclopentanone ring is rotationally disordered over two sites with an occupancy ratio of 0.579 (4):0.421 (4). The molecular structure of (I) is stabilized by an intramolecular C—H...O hydrogen bond, which generates anS(7) ring motif. In the crystal, the molecules are linkedviaweak C—H...O hydrogen bonds, which generateR22(16) ring motifs in (I) andC(8) chains in (II). In both structures, the crystal packing also features C—H...π interactions. The crystal studied of compound (I) was twinned by non-merohedry. The twin component is related by the twin law [−1 0 0 −0.101 1 −0.484 0 0 −1] operated by a twofold rotation axis parallel to thebaxis. The structure of (I) was refined with a twin scale factor of 0.275 (2).

Structural Study of an Unusual Diels-Alder Adduct

1992 ◽  
Vol 45 (12) ◽  
pp. 2089 ◽  
Author(s):  
EL Ghisalberti ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Diffraction Study ◽  
Structural Study ◽  
Spectroscopic Studies ◽  
Diels Alder ◽  
X Ray Diffraction ◽  
X Ray ◽  
Naturally Occurring ◽  
Chemical Evidence ◽  
Alder Adduct

The structure of the compound obtained on heating the naturally occurring clerodane furanoditerpene (1) had been formulated as (2) on the basis of spectroscopic studies. A single-crystal X-ray diffraction study on the dihydro derivative of (2) has confirmed this and provides support for the stereochemistry previously assigned to (1) on the basis of chemical evidence.

scholarly journals Competitive Diels–Alder and ene addition of N-arylmaleimides to 7-dehydrocholesteryl acetate

1992 ◽  
Vol 70 (11) ◽  
pp. 2730-2744 ◽  
Author(s):  
William J. Leigh ◽  
Donald W. Hughes ◽  
D. Scott Mitchell
Keyword(s):  
Molecular Mechanics ◽  
Nmr Spectra ◽  
Benzene Solution ◽  
Diels Alder ◽  
Spectroscopic Techniques ◽  
Two Dimensional ◽  
A Minor ◽  
C Nmr ◽  
Alder Adduct ◽  
Ene Addition

Thermolysis of N-phenyl, N-para-biphenyl, and N-para, para′-terphenylmaleimide with 7-dehydrocholesteryl acetate in benzene solution at 200 °C yields mixtures of four cycloadducts in relative yields that are essentially independent of the maleimide substituent. The three major products are those of ene addition to C7 of the steroid with abstraction of the proton at C9 or C14. The α-endo-Diels-Alder adduct is formed as a minor product. The structures of the adducts have been elucidated on the basis of one- and two-dimensional 1H and 13C NMR spectroscopic techniques, including homonuclear 1H decoupling, NOE, 1H–1H COSY, heteronuclear 1H–13C shift correlation, and TOCSY 2-D experiments, and the results of molecular mechanics (MMX) calculations. The combination of these techniques has made it possible to almost completely assign the 1H and 13C NMR spectra for two of the ene adducts and the Diels–Alder adduct from reaction of 7-dehydrocholesteryl acetate with N-phenyl maleimide.

Fast‐reprocessing, Post‐adjustable, Self‐healing Covalent Adaptable Networks with Schiff base and Diels‐Alder Adduct

2022 ◽  
pp. 2100777
Author(s):  
Xiwei Xu ◽  
Songqi Ma ◽  
Sheng Wang ◽  
Binbo Wang ◽  
Hongzhi Feng ◽  
...  
Keyword(s):  
Schiff Base ◽  
Diels Alder ◽  
Self Healing ◽  
Alder Adduct
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