HETEROCYCLES
An International Journal for Reviews and Communications in Heterocyclic ChemistryWeb Edition ISSN: 1881-0942
Published online by The Japan Institute of Heterocyclic Chemistry
Regular Issue
Vol. 24, No. 6, 1986
Published online:
■ Convertion of 4,5,6-Triaryl-2-pyranamines and 4,6-Diarly-5-benzoyl-2-pyranamines into Pyrones, Pyridones and Pyridines
Margarita Quinteiro, Nazario Martín, Carlos Seoane, and José L. Soto*
*Departamento de Química Orgánica, Facultad de Química, Universidad Complutense de Madridas, Ciudad Universitaria, E-28040 Madrid, Spain
Abstract
Treatment of 4,5,6-triaryl-2-pyranamines I with nitrosylsulfuric acid brings about their conversion into triarylpyrones IV. Their 5-benzoyl analogues V afford the corresponding 2-pyrones (VI), together with pyridones VII, resulting from ring opening of V. On the other hand, I undergoes a ring transfomation into aminopyridines X by reaction with ammonium acetate.
Published online:
■ Novel Formation of 11,12-Dihydro-6H-quino[2,3-b][1,5]benzodiazepines: Reaction of 2-Chloroquinoline-3-carbaldehydes with o-Phenylenediamine
Nanduri Bhanumathi, Kakulapati Rama Rao, and Prahlad Balvantrao Sattur*
*Regional Research Laboratory, Hyderabad 500 007, India
Abstract
The reaction of 2-chloroquinoline-3-carbaldehydes with o-phenylenediamine gave 2-chloro-3-(2-benzimidazolyI)quinoline (VI), 6H-quino[2,3-b][1,5]benzodiazepine (IV) and 11,12- dihydro-6H-quino[2,3-b][1,5]benzodiazepine (V). The latter (V) is assumed to be formed from (IV) by reduction with the benzimidazoline intermediate (III), a hydrogen donor.
Published online:
■ The Preparation of "Elongated" Nicotine Analogues
Henry V. Secor* and Jeffery I. Seeman
*Research Center, Philip Morris USA, P.O. Box 26853, Rcihmond, Vierginia 23261, U.S.A.
Abstract
The preparation of four nicotine analogues having one or two additional methylene units between the N-rnethylpyrrolidinyl moiety and the aromatic ring are reported. Also prepared are the corresponding nornicotine and myosmine analogues. The course of the Späth condensation used in these syntheses is examined, especially with regard to possible proton transfer reactions.
Published online:
■ Synthesis of 1,7-Dioxaspiro[5.5]undecanes
Arthur F. Kluge*
*Institute of Organic Chemistry, Syntex Discovery Research, 3401 Hillview Avenue, Palo Alto, California 94304, U.S.A.
Abstract
Method for preparing 1,7-dioxaspiro[5.5]undecanes are reviewed and are classified according to synthetic strategy. A major strategic category covered by this review includes methods that rely an the acid-catalyzed ketalization of a 1,9-dihydroxynonan-5-one or some functionally equivalent unit containing the ketone group in a masked form such as an enol ether, a thioenol ether, a dithioketal, or a hydrazone. Other strategies detailed in this review include Michael-type cyclization, intramolecular directed aldol reaction of a trimethylsilyl enol ether with a dioxocarbocation, spirocycization of hypoiodities, hetero Diels-Alder cycloadditions, and ring expansion. These various strategies are also discussed in terms of their control of stereochemistry.