J. Yovell

Photoreactions of a methylene-spirane and dispirane with Fe(CO)5. σ,π-Complex formation from a double cyclopropane rearrangement

The major product from the photoreaction of 4-methylenedispiro[2,1,2,3]decane (5) with Fe(CO)5 is shown to be a tricarbonyliron σ,π-complex of structure (7), whereas the products from 4-methylenespiro[2,4]heptane (9) and 4-methylenespiro[2,5]octane (15) are the respective bi-cyclic enones (12)–(13) and (16).

AlCl3-induced reactions of vinylcyclopropanes : Dimerizations and additions with rearrangement

Abstract 1,1-ethano-2-methylenecyclonexane 5, 1,13,3-diethano-2-methylenecyclohexane 6, α-cyclopropylstryene 7 and its p-chloro and p-methoxy derivatives 8 and 9, 1-methyl-1-cyclopropylethylene 10, and 1,1-dicyclopropy-lethylene 11 were subjected to the action of AlCl3OEt2 4 in ether. Monomeric (12-15) and duneric (16, 17) homoallylic chlorides as well as some polymeric products were obtained. The mechanism and substituents effects are discussed and spectral data (IR, PMR and MS) of the products are presented.

Uncatalysed olefin metathesis reaction

The 1,1,2,2-tetracyanodispiro[3.0.2.x]alkanes (7a and b) manifest two modes of thermal cleavage (180°C) of the 4-membered ring, giving rise to the respective 4-dicyanomethylene-spiro [2.x]alkanes (9a and b) with extrusion of vinylidenecyanide, and the respective intramolecular [3 + 4] cycloaddition products (11a and b) in a ratio depending on the solvent used; the formation of the respective olefin metathesis product (3) from the reaction of TCNE with (1) in MeNO2 is explained in terms of an initial formation of the thermally unstable cyclobutane (2), undergoing ring-fusion to yield the products.

Intramolecular [3 + 4] cycloaddition in substituted dispiro[2,3,x]alkanes. A new pathway to polycyclic olefins containing cycloheptene

A novel cycloreaction involving intramolecular addition of cyclopropane to a tetrasubstituted cyclobutane contained in a dispiro-system to form a seven-membered ring is described.