Base-induced solvolyses of [3.2.1]Bicyclic alpha,alpha '-dichloro ketones - 1,3-transposition and ring-contraction

Authors
Fohlisch, B Radl, A Schwetzler-Raschke, R Henkel, S
Citation
B. Fohlisch et al., Base-induced solvolyses of [3.2.1]Bicyclic alpha,alpha '-dichloro ketones - 1,3-transposition and ring-contraction, EUR J ORG C, (22), 2001, pp. 4357-4365
Citations number
30
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
ISSN journal
1434193X → ACNP
Issue
22
Year of publication
2001
Pages
4357 - 4365
Database
ISI
SICI code
1434-193X(200111):22<4357:BSO[A'>2.0.ZU;2-K
Abstract
2,4-Dichlorobicyclo[3.2.1]oct-6-en-3-one (1) and its spirocyclopropane (4) and 8-oxa analogues (15, 16) react with methanolic sodium methoxide to furn ish bicyclic alpha -oxo-acetals (3b, 5b, 17, 18) through an enolization/ion ization mechanism. With trifluoroethanol/sodium trifluoroethoxide, the corr espending trifluoroethyl acetals (3a and 5a) are formed. Basic hydrolysis a ffords 2-endo-hydroxynorbornene-2-exo-carboxylic acid (20x) and the 7-oxa a nalogues (22x, 23x), presumably through benzilic acid rearrangement of the alpha -diketones.