| 摘要 |
PURPOSE:The reaction of an azetidin-2-one derivative with a phosphorous triester or phosphorous acid triamide affords the titled compound that is important as a synthetic intermediate of penem-3-carboxylic acids, antibiotics. CONSTITUTION:The reaction between a compound of formula I [R<1> is H, alkyl, R<4>A (R<4> is hydroxyl, alkoxy, acyloxy; A is alkylidene that may be substituted with trifluoromethyl); R<2> is alkyl, alkenyl, aralkyl; R<3> is carboxyl-protecting group; X is O, S; Y is O, S] and a phosphorous triester or phosphorous acid triamide is conducted in a solvent such as methanol or propanol to give the compound of formula II. The phosphorous triester is expressed by (R<4>)3P (R<4> is alkoxy, dialkylamino) and the amount used is 2-20 equivalents per the compound of formula I. |
