W. Adam*, E. Crämer
Dec 1, 1987
Citations
0
Influential Citations
2
Citations
Journal
Chemische Berichte
Abstract
1-Oxadispiro[2.1.2.2]nonane (1), prepared in 62% yield by epoxidation of 5-methylenespiro[2.4]heptane with m-chloroperbenzoic acid, gave on treatment with trifluoroacetic acid in CCl4 the isomeric hydroxy esters 5-(hydroxymethyl)-5-(trifluoroacetoxy)-(2a) and 5-hydroxy-5-[(trifluoroacetoxy)methyl]spiro[2.4]heptane (2b) as major products. Hydrolysis of 2a, b with KOH in ethanol led to 5-hydroxy-5-(hydroxymethyl)spiro[2.4]heptane (3) in 61% yield. As minor products were isolated the isomeric unsaturated alcohols 5-(hydroxymethyl)spiro[2.4]hept-5-ene and -4-ene (4a, b), spiro [2.4]heptane-5-carboxaldehyde (5) (which was readily autoxidized to carboxylic acid 6), and the isomeric acetals 7-(spiro[2.4]hept-5-yl)-6,8-dioxadispiro[2.1.4.2]undecane (7a, b). These products were all rationalized in terms of standard carbenium ion chemistry of the protonated oxirane. No evidence could be provided for transannular ring expansion of the spirocyclopropane moiety to yield bridgehead-substituted norbornanes.