Patent ID: 6201138
Filing Date: 2001-03-13
Classification: B01J,C07D

Abstract:
Process for the isormerization of a .gamma.,.delta.-epoxyalkene or a .gamma.,.delta.-epoxycycloalkene having the formula ##STR7##to the corresponding 2,5-dihydrofuran having the formula ##STR8##wherein each R.sup.1 is hydrogen or up to 2 R.sup.1 substituents each may be alkyl of up to about 8 carbon or collectively straight or branched chain alkylene of up to about 8 carbon atoms, which comprises contacting the .gamma.,.delta.-epoxyalkene or a .gamma.,.delta.-epoxycycloalkene in the liquid phase at a temperature of about 50 to 200.degree. C. with a solution of a catalytic amount of a catalyst comprising(1) at least one quaternary organic onium iodide compound containing at least 6 carbon atoms; of the formula ##STR9##whereineach R.sup.2 is independently selected froem hydrogen, alkyl or substituted alkyl moieties having up to about 20 carbon atoms, cycloalkyl or substituted cycloalkyl having about 5 to 20 carbon atoms, aryl or substituted arvl having about 6 to 20 carbon atoms, ferrocenyl; or when Y is P, each R.sup.2 also may be selected from alkoxy of up to about 20 carbon atoms, cycloalkoxy of about 5 to 20 carbon atoms, aryloxy of 6 to 10 carbon atoms or halogen;two or three R.sup.2 substituents collectively may represent joined hydrocarbylene groups which form a mono- or poly-cyclic ring with the Y atom to which they are bonded;each R.sup.3 is independently selected from hydrocarbylene moieties or substituted hydrocarbylene moieties;x is 0 or 1, andY is N, P or As;(2) an organometallic compound having the formula(R.sup.7).sub.n --Sn--Hal.sub.(4-n) or (R.sup.7).sub.4 --Sb--Halwhereineach R.sup.7 independently is selected from alkyl or substituted alkyl moieties having up to about 20 carbon atoms, cycloalkyl or substituted cycloalkyl having about 5 to 20 carbon atoms, aryl or substituted aryl having about 6 to 20 carbon atoms,Hal is bromo or iodo; andn is 1, 2, 3 or 4; in an inert organic solvent.