Synthesis of tetrahydrofurans by cyclization of homoallylic alcohols with iodine/iodine(III).
Tetrahydrofuran derivatives can be obtained by cyclofunctionalization of homoallylic alcohols bearing a terminal double bound by using [hydroxy(tosyloxy)iodo]benzene (HTIB, Koser's reagent) in the presence of a catalytic amount of I(2) (20 mol %) in MeOH under mild conditions. This transformation is an overall 5-endo-trig cyclization, which occurs by two different pathways. The first is a 4-exo-trig cyclization followed by ring expansion, whereas the second is an electrophilic addition followed by a 5-endo-tet cyclization.
Institut für Organische Chemie, Fakultät für Chemie und Mineralogie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany.
Ramon S
RS
Vasconcelos
Luiz F
LF
Silva
Athanassios
A
Giannis
D003500:Cyclization; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry; D007455:Iodine / Q000737:chemistry*; D015394:Molecular Structure; D020005:Propanols / Q000737:chemistry*; D013237:Stereoisomerism
D005663:Furans; D020005:Propanols; C018674:tetrahydrofuran; C006463:allyl alcohol; D007455:Iodine