Paul J. Kropp

Photochemistry of alkyl halides. 10. Vinyl halides and vinylidene dihalides

Proprietes photochimiques du dimethyl-2,4 iodo-3 pentene-2, des iodo-1 cycloalcenes, des (halogenomethylene) cycloalcanes et des (dihalogenomethylene) cyclohexanes. Formation de produits radicalaires et ioniques. Mecanismes. Donnees spectrales UV, IR, RMN 1 H

Surface-mediated reactions. 5. Oxidation of sulfides, sulfoxides, and alkenes with tert-butyl hydroperoxide

Abstract Silica gel mediates the reactivity of (CH 3 ) 3 COOH, affording a convenient, environmentally benign method for oxidizing sulfides, sulfoxides, and alkenes. Electrophilic oxidation of sulfides and alkenes (Scheme 1A) and nucleophilic oxidation of sulfoxides (Scheme 1B) are apparently involved. Basic alumina mediates the oxidation of sulfoxides.

Photochemistry of alkyl halides—VII : Cyclopropanation of alkenes

Abstract The previously observed cyclopropaoation of alkenes by irradiation of diiodomethane (I) in their presence has been studied in more detail and found to be a synthetically useful procedure which is significantly less subject to steric effects than the traditional Simmons-Smith method. The results from photocyclopropanation of a variety of alkenes are summarized in Tables 1 and 3–4. In a number of cases the photochemical procedure afforded improved results over the Simmons-Smith method, particularly with sterically congested alkenes. Cycloalkenes showed relative rates of photocyclopropanation as a function of ring size similar to those of the Simmons-Smith method (Table 5). However, the photocyclopropanation reaction exhibited steadily increasing relative rates with increasing substitution about the double bond—in contrast with the Simmons-Smith method (Table 6), in which steric effects offset increasing nucleophilicity of the alkene with increasing substitution. The α-iodocation 2 is suggested as the methylene transfer species. In the presence of lithium bromide cation 2 was trapped to afford bromoiodomethane.

Photochemistry of alkyl halides. 11. Competing reaction via carbene and carbocationic intermediates

Analyse isotopique des produits (octene-1 et cyclohexene) obtenus par irradiation des dideuterio-1,1 et -2,2 iodo-1 octane via α-elimination principalement. Processus de competition mettant en jeu des carbenes ainsi que des intermediaires radicalaires et carbocationiques

Photochemistry of alkyl halides, 5. 2,4-dehydroadamantane and protoadamantene from 2,-bromo- and 2-iodoadamantane

Bei der Photolyse der 2-Halogen-adamantane (I) erhalt man je nach den angewandten Bedingungen in Diethylether oder Methanol Mischungen aus Adamantan (II), den durch innermolekulare Einschiebung gebildeten Dehydroverbindungen (III) und (IV) sowie den AdamantanylQ-ethern (V).

(1,3-Dithiolan-2-YL)Acetonitrile: A Versatile Three-Carbon Building Block1

Abstract Recently, in connection with other work, we required cyano-acetaldehyde as a usefully functionalized three-carbon building block. Although first reported in 18893 as an isolable compound, cyanoacetaldehyde has appeared in the literature only as various derivatives since that time.4 Indeed, in these laboratories, all attempts to prepare cyanoacetaldehyde have failed because of its great instability.