Formation of Dihydroaza-azulanones Possessing Spirocyclic Moieties: [8+2] Type Cycloaddition Reactions of Iminotropones to an Exocyclic Double Bond of 8-Oxoheptafulvene

Heterocycles ◽  
1995 ◽  
Vol 41 (10) ◽  
pp. 2181 ◽  
Author(s):  
Katsuhiro Saito ◽  
Yuka Saito ◽  
Masayuki Tomita ◽  
Hiroshi Taniguchi ◽  
Hirofumi Okabayashi
Keyword(s):  
Double Bond ◽  
Exocyclic Double Bond ◽  
Cycloaddition Reactions

π-Facial Selectivity in 1,3-Dipolar Cycloaddition Reactions of α-Methylidene-γ-lactone Substituted by 4-Methyl-2,6,7-trioxabicyclo[2.2.2]octan-1-yl Group in γ-Position

2002 ◽  
Vol 67 (3) ◽  
pp. 353-364 ◽  
Author(s):  
Petr Melša ◽  
Ctibor Mazal
Keyword(s):  
Double Bond ◽  
Carboxylic Acid ◽  
Nitrile Oxide ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Enantiomerically Pure ◽  
Nitrile Imine ◽  
Facial Selectivity ◽  
Excellent Selectivity

Diastereoselectivity of 1,3-dipolar cycloaddition reactions of benzyl azide, diazomethane, a nitrile oxide and a nitrile imine to α-methylidene-γ-lactone dipolarophile was effectively controlled by a bulky γ-substituent, 4-methyl-2,6,7-trioxabicyclo[2.2.2]octan-1-yl in γ-position of the dipolarophile. The dipoles added from the less hindered face of the double bond with an excellent selectivity. Enantiomerically pure dipolarophile was prepared from the easily available (S)-5-oxotetrahydrohydrofuran-2-carboxylic acid.

Cycloaddition reactions across the carbon-carbon double bond of thiirene 1,1-dioxide

1984 ◽  
Vol 49 (7) ◽  
pp. 1300-1302 ◽  
Author(s):  
Mitsuo Komatsu ◽  
Yasuo Yoshida ◽  
Masatoshi Uesaka ◽  
Yoshiki Ohshiro ◽  
Toshio Agawa
Keyword(s):  
Double Bond ◽  
Cycloaddition Reactions ◽  
Carbon Double Bond

scholarly journals Stereoselective total syntheses of (±)-sinularene and (±)-5-epi-sinularene: a general intramolecular Diels–Alder approach to tricyclic sesquiterpenes

1985 ◽  
Vol 63 (4) ◽  
pp. 993-995 ◽  
Author(s):  
Kazimierz Antczak ◽  
John F. Kingston ◽  
Alex G. Fallis
Keyword(s):  
Double Bond ◽  
Methyl Ester ◽  
Total Synthesis ◽  
Ring System ◽  
Diels Alder ◽  
Exocyclic Double Bond ◽  
Total Syntheses ◽  
Methyl Group ◽  
Secondary Hydroxyl ◽  
Selective Hydrogenolysis

Stereoselective total synthesis of (±)-sinularene and (±)-5-epi-sinularene are described. The sequence employs a "blocked" cyclopentadiene in which the cyclopropane unit also serves as a latent methyl group. Thus intramolecular [4 + 2] cycloaddition of the substituted methyl spiro[2.4]hepta-4,6-dien-1-yl)-2-pentenoate 11 affords 5-benzyloxy-6-isopropyl-8-carbomethoxytetracyclo[5.4.01,7.02,4.02,9]undec-10-ene (12) which after selective hydrogenolysis generates the tricyclo[4.4.01,6.02,8]decane (sinularene) ring system. Removal of the secondary hydroxyl function (Ph3P/CCl4/CH3CN; H2/Pd/C), reduction of the methyl ester (LiAlH4), and introduction of the exocyclic double bond (acetate pyrolysis, 550 °C) completes the synthesis of (±)-sinularene in 14 steps from cyclopentadiene. A parallel series of reactions employing the isopropyl epimer of 12 affords (±)-5-epi-sinularene.

Structurally original oxathioethers macrocycles containing an exocyclic double-bond: synthesis, characterization, reactivity, and coordination

Tetrahedron ◽  
2014 ◽  
Vol 70 (35) ◽  
pp. 5650-5658 ◽  
Author(s):  
Guillaume Carel ◽  
Alina Saponar ◽  
Nathalie Saffon ◽  
Marc Vedrenne ◽  
Stéphane Massou ◽  
...  
Keyword(s):  
Double Bond ◽  
Exocyclic Double Bond
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