HYDROGEN MIGRATIONS IN A CONSTRAINED CYCLOHEXYLIDENE - HAX HEQ SHIFT RATIOS IN THERMAL AND PHOTIC BAMFORD-STEVENS REACTIONS/

Authors
STERN AG ILAO MC NICKON A
Citation
Ag. Stern et al., HYDROGEN MIGRATIONS IN A CONSTRAINED CYCLOHEXYLIDENE - HAX HEQ SHIFT RATIOS IN THERMAL AND PHOTIC BAMFORD-STEVENS REACTIONS/, Tetrahedron, 49(36), 1993, pp. 8107-8118
Citations number
54
Categorie Soggetti
Chemistry Inorganic & Nuclear
Journal title
Tetrahedron → ACNP
ISSN journal
00404020
Volume
49
Issue
36
Year of publication
1993
Pages
8107 - 8118
Database
ISI
SICI code
0040-4020(1993)49:36<8107:HMIACC>2.0.ZU;2-1
Abstract
Homobrexan-2-one was synthesized labeled in the alpha-position with C- 13 and also with an axial or equatorial D. Their p-tosylhydrazone Li s alts were thermolyzed and photolyzed (Bamford-Stevens reaction) to gen erate putative singlet carbenes, which undergo competitive 1,3-inserti on to a tetracycle and 1,2-H (or D) shift to an alkene. After correcti on for isotope effects, the Hax/Heq shift ratios were ca. 1.7 and ca. 1.2 for the thermal and photic processes, respectively. These ratios a re free of chair-boat and epimerization ambiguities.