INTRAMOLECULAR [2+2] CYCLOADDITION AND SEQUENTIAL RING EXPANSION

Authors
ZHANG W COLLINS MR MAHMOOD K DOWD P
Citation
W. Zhang et al., INTRAMOLECULAR [2+2] CYCLOADDITION AND SEQUENTIAL RING EXPANSION, Tetrahedron letters, 36(16), 1995, pp. 2729-2732
Citations number
25
Categorie Soggetti
Chemistry Inorganic & Nuclear
Journal title
Tetrahedron letters → ACNP
ISSN journal
00404039
Volume
36
Issue
16
Year of publication
1995
Pages
2729 - 2732
Database
ISI
SICI code
0040-4039(1995)36:16<2729:I[CASR>2.0.ZU;2-5
Abstract
Free radical ring expansion of fused-cyclobutanones gives bicyclic ket ones expanded by three and four carbons, with the carbonyl group beta to the ring junction. Four-carbon ring expansion shows stereoselectivi ty favoring the trans-fused product 6-trans. The radical precursor cyc lobutanones are readily prepared by intramolecular[2 + 2] cycloadditio n of ketenes or keteniminium salts to olefins.