摘要
The reaction of monocyclic oxyphosphorane compounds 1a,1b,1c with ethylene glycol in pyridine was studied by P-31 NMR. The results show that compound 1a with an unsaturated five-membered ring reacts faster than compound 1b with a saturated ring attached by two trans p-nitro phenyl groups, which in turn reacts greatly faster than the cis- compound 1c. To interpret the mechanism, a hexacoordinate intermediate whose five-membered ring occupied the e-, e- position was proposed.
The reaction of monocyclic oxyphosphorane compounds 1a,1b,1c with ethylene glycol in pyridine was studied by P-31 NMR. The results show that compound 1a with an unsaturated five-membered ring reacts faster than compound 1b with a saturated ring attached by two trans p-nitro phenyl groups, which in turn reacts greatly faster than the cis- compound 1c. To interpret the mechanism, a hexacoordinate intermediate whose five-membered ring occupied the e-, e- position was proposed.
