OH ▁+ ▁CO Cl 2 ▁→ ▁Ph O ( CO ) Cl ▁+ ▁H Cl ▁▁ 2 ▁Ph O ( CO ) Cl ▁→ ▁Ph O ( CO ) OP h ▁+ ▁CO Cl 2 ▁ ▁Over all ▁reaction ▁is : ▁▁ 2 ▁Ph OH ▁+ ▁CO Cl 2 ▁→ ▁Ph O ( CO ) OP h ▁+ ▁ 2 ▁H Cl ▁ ▁Ox id ative ▁car b ony lation ▁Ox id ative ▁car b ony lation ▁is ▁an ▁alternative ▁to ▁ph os gen ation . ▁The ▁advantage ▁is ▁the ▁avoid ance ▁of ▁ph os g ene . ▁ ▁Using ▁co pper ▁catal yst s , ▁dim eth yl car bon ate ▁is ▁prepared ▁in ▁this ▁way : ▁▁▁ 2 ▁Me OH ▁+ ▁CO ▁ ▁+ ▁▁ 1 / 2 ▁O 2 ▁→ ▁Me O ( CO ) OM e ▁+ ▁H 2 O ▁Di phen yl ▁carbon ate ▁is ▁also ▁prepared ▁similarly , ▁but ▁using ▁p all ad ium ▁catal yst s . ▁ ▁The ▁P d - catal yz ed ▁process ▁requires ▁a ▁c oc atal yst ▁to ▁recon vert ▁the ▁P d ( 0 ) ▁to ▁P d ( II ). ▁ ▁Mang an ese ( III ) ▁ac ety lac eton ate ▁has ▁been ▁used ▁commer cially . ▁ ▁Re action ▁of ▁carbon ▁dio x ide ▁with ▁epo x ides ▁The ▁reaction ▁of ▁carbon ▁dio x ide ▁with ▁epo x ides ▁is ▁a ▁general ▁route ▁to ▁the ▁prepar ation ▁of ▁cy clic ▁ 5 - member ed ▁carbon ates