A. U. Vinod

The reaction of cyclohexyl isocyanide and dimethyl acetylenedicarboxylate with o- and p-quinones: a novel synthesis of iminolactones

The 1:1 intermediate generated by the addition of cyclohexyl isocyanide to dimethyl acetylenedicarboxylate is trapped by quinones to yield iminolactones in good yields.

A facile three-component reaction involving [4+1] cycloaddition leading to furan annulated heterocycles

The in situ generated quinone methides from 4-hydroxycoumarin and 4-hydroxy-6-methylpyrone with various aldehydes underwent facile reaction with cyclohexyl isocyanide to produce furocoumarins in good yields. Quinone methides from 4-hydroxy-1-methylquinolinone afforded furoquinolones. The reaction presumably occurs via a [4+1] cycloaddition followed by a [1,3] H shift.

Dipolar cycloaddition of carbonyl ylides to para-quinoneimides: a facile route to bicyclo[3.2.1] and [2.2.1] systems☆

Five- and six-membered carbonyl ylides formed from rhodium carbenoids add to p-quininoneimides to afford bicyclic compounds in good yields.

The reaction of cyclohexyl isocyanide and dimethyl acetylenedicarboxylate with aldehydes: a novel synthesis of 2-aminofuran derivatives

The 1:1 intermediate generated by the additon of cyclohexyl isocyanide to dimethyl acetylenedicarboxylate is trapped by aldehydes to yield 2-aminofuran derivatives in good yields.

Triphenylphosphine promoted addition of dimethyl acetylenedicarboxylate to 1,2-benzoquinones: facile synthesis of novel γ-spirolactones

The addition of dimethyl acetylenedicarboxylate to o-quinones in the presence of triphenylphosphine leading to highly functionalised γ-spirolactones is reported.

Corrigendum to “Dipolar cycloaddition of carbonyl ylides to para-quinoneimides: a facile route to bicyclo[3.2.1] and [2.2.1] systems”: [Tetrahedron Letters 42 (2001) 2045–2046]

The authors regret that an error occurred in the assignment of the stereochemistry for the products 3a and 5(a–c) in Figure 1 and Schemes 1 and 3. The correct assignments are shown below.

Novel cycloaddition reactions ofo-benzoquinones and related chemistry

Abstracto-Benzoquinone is a unique conjugated 1,2-dione that can exhibit diverse cycloaddition modes, participating either as carbodiene, heterodiene, dienophile or heterodienophile. With electron-rich dienes, benzodioxins are formed in excellent yields. Pentafulvenes including 6-vinylfulvenes normally give rise to bicyclo [2.2.2] adducts. Exceptions are observed with cycloalkylfulvenes where the fulvenes undergo rearrangement to cyclopentadiene derivatives prior to cycloaddition, resulting in benzodioxins.o-Benzoquinones participate as dipolarophiles on treatment with nitrile oxides and carbonyl ylides yielding highly oxygenated novel spiro compounds. Triphenylphosphine catalyzed addition of DMAD too-benzoquinones afforded another class of novel spirolactones. The bicyclo [2.2.] octene diones derived fromo-benzoquinones undergo a number of synthetically useful transformations.