A type 1 intramolecular Dials-Alder approach to the mniopetals: Intervention of a thermal [1,5] hydrogen shift

Authors
Allen, A Gordon, DM
Citation
A. Allen et Dm. Gordon, A type 1 intramolecular Dials-Alder approach to the mniopetals: Intervention of a thermal [1,5] hydrogen shift, I J CHEM B, 38(3), 1999, pp. 269-273
Citations number
15
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
INDIAN JOURNAL OF CHEMISTRY SECTION B-ORGANIC CHEMISTRY INCLUDING MEDICINAL CHEMISTRY
ISSN journal
03764699 → ACNP
Volume
38
Issue
3
Year of publication
1999
Pages
269 - 273
Database
ISI
SICI code
0376-4699(199903)38:3<269:AT1IDA>2.0.ZU;2-U
Abstract
An approach to mniopetals A-F (1-6) based on a type 1 intramolecular Diels- Alder (IMDA) reaction has been investigated. The substrate 12 for the envis ioned IMDA reaction is either unreactive or decomposes upon exposure to Lew is acids over a range of temperatures, heating a solution of 12 in toluene at 110 degrees C, however, produces itaconate 14 in 80% yield. The stereosp ecific formation of 14 from 12 can be rationalized by a thermal [1,5] hydro gen shift. Analogously, thermolysis of alkenyl maleates 15a-c at 110 degree s C in toluene or 1,2-dibromoethane gives good yields of itaconates 16a-c, respectively.