Results 71 to 80 of about 276 (104)

Ring expansion of 3-acetylcoumarin by diazoethane: lactones derived from oxepin, oxocin, and oxonin

Journal of the Chemical Society, Perkin Transactions 1, 1974
Diazoethane partly alkylates 3-acetylcoumarin giving 3-acetyl-4-ethylcoumarin, and partly expands the lactone ring giving, after addition of a second molecule of diazoethane, the benzoxepinopyrazoline (IX) as a racemate of assigned stereochemistry.
Robert Clinging, Francis M. Dean, Leonard E. Houghton   +2 more
openaire   +1 more source

Novel Synthesis of Azocine, Azepine, Oxocine, and Oxepine Derivatives by Palladium-catalyzed Medium-Ring Formation from Bromoallenes

HETEROCYCLES, 2003
AbstractFor Abstract see ChemInform Abstract in Full Text.
Hiroaki Ohno, Hisao Hamaguchi, Miyo Ohata, Shohei Kosaka, Tetsuaki Tanaka   +4 more
openaire   +1 more source

Novel synthesis of oxocine derivatives by Wittig olefination and intramolecular Heck reaction via 8-endo trig cyclization

Tetrahedron Letters, 2008
A concise and efficient method for the preparation of oxocine derivatives is described via sequential Wittig and intramolecular Heck reactions. The method is highly regioselective and affords high yields of the products.
K.C. Majumdar, B. Chattopadhyay, B. Sinha   +2 more
openaire   +1 more source

Iron-Catalyzed Reductive Ring-Rearrangement Reaction of Bridged Benzo[b]oxocin-4-ones with Grignard Reagents to Afford Bridged Benzo[b]oxocin-2-ols

Organic Letters
An iron-catalyzed reductive ring-rearrangement reaction of bridged benzo[b]oxocin-4-ones with Grignard reagents to produce bridged benzo[b]oxocin-2-ols is reported. Mechanistic studies indicate that an iron redox catalysis cycle involving oxidative addition to the C-O bond by low-valence iron and β-methoxyl elimination as key steps operates in this ...
Yishuai Fan, Haoran Yang, Ri Peng, Dunru Zhu, Ruwei Shen   +4 more
openaire   +2 more sources

Novel Palladium-Catalyzed Oxidative Intramolecular Cyclization of β-Citronellol with H2O2: A Green and Selective Process to Synthesize Oxocine

Catalysis Letters, 2017
In this work, we have found that the pair palladium acetate/hydrogen peroxide promoted a rare oxidative cyclization of β-citronellol, resulting in the selective formation of a novel monoterpene derivative (i.e., (Z)-4,8,8-trimethyl-3,4,5,8-tetrahydro-2H-oxocine). The activity of different palladium-catalysts was assessed. Palladium acetate was the most
M. J. da Silva, Jesus Avendano Villarreal   +1 more
openaire   +1 more source

ChemInform Abstract: RING EXPANSION OF 3‐ACETYLCOUMARIN BY DIAZOETHANE, LACTONES DERIVED FROM OXEPIN, OXOCIN, AND OXONIN

Chemischer Informationsdienst, 1974
AbstractDie Umsetzung des Cumarins (I) mit Diazoäthan (II) verläuft teilweise unter Alkylierung zu (III) und teilweise unter Ringerweiterung zu den Derivaten (IV)‐(VII).
ROBERT CLINGING, FRANCIS M. DEAN, LEONARD E. HOUGHTON   +2 more
openaire   +1 more source

Synthesis of Oxepin‐ and Oxocin‐Annulated Pyrimidine Derivatives by Claisen Rearrangement and Ring Closing Metathesis/Ring Closing Enyne Metathesis.

ChemInform, 2007
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Krishna C. Majumdar, Pradip K. Maji, Habibur Rahaman, Brindaban Roy   +3 more
openaire   +1 more source

A novel method for the synthesis of 5,6-dihydro-4H-oxocin-4-ones: 6-endo-dig versus 8-endo-dig cyclizations

Tetrahedron Letters, 2003
AbstractFor Abstract see ChemInform Abstract in Full Text.
N. Rosas, P. Sharma, C. Alvarez, E. Gomez, Y. Gutierrez, M. Mendez, R. A. Toscano, L. A. Maldonado   +7 more
openaire   +1 more source

A Synthesis of Substituted 3,6-Dihydro-1H-benzo[c]oxocines via Claisen Rearrangement and Ring-closing Metathesis

HETEROCYCLES, 2002
Started from isovanillin, based on Claisen rearrangement and ring-closing metathesis (RCM) reaction, a series of substituted 3,6-dihydro-1H-benzo[c]oxocines were synthesized in moderate yields.
Eng-Chi Wang, Chin-Cheng Wang, Ming-Kun Hsu, Keng-Shiang Huang   +3 more
openaire   +1 more source

ChemInform Abstract: Regioselective Synthesis of Oxepin‐ and Oxocin‐Annulated Quinolines by Combined “Claisen‐Rearrangement/Olefin‐Metathesis” Reactions.

ChemInform, 2008
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Sven Rotzoll, Helmar Goerls, Peter Langer   +2 more
openaire   +1 more source