01412nas a2200229 4500008004100000022001400041245008200055210006900137260008600206300001800292490000700310520060700317653000600924653001500930653001500945653002200960653001500982653002400997100002701021700002501048856010901073 2010 eng d a0039-791100aAddition of a silyl ketene acetal to alpha,beta-unsaturated cyclic anhydrides0 aAddition of a silyl ketene acetal to alphabetaunsaturated cyclic a325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USAbTAYLOR & FRANCIS INCcJUL aPII 9247712650 v403 a
Addition of [1-methoxy-2 methyl-1-propenyl)-oxy] trimethylsilane (MTS) to unsymmetrical ,-unsaturated cyclic anhydrides (namely, itaconic anhydride and citraconic anhydride) as well as symmetrical anhydrides (namely, maleic anhydride and 2,3-dimethylmaleic anhydride) was investigated. Itaconic anhydride isomerizes to citraconic anhydride in the presence of MTS. In the presence of Lewis acid catalysts (Yb(OTf)3/CH2Cl2), MTS adds to itaconic anhydride at room temperature in a 1,4-fashion. 1,2-Addition is the preferred pathway with both 2,3-dimethyl maleic anhydride and citraconic anhydride.
10a110a2-Addition10a4-addition10acyclic anhydrides10aLewis acid10aSilyl ketene acetal1 aGnaneshwar, Rudhramyna1 aSivaram, Swaminathan uhttp://library.ncl.res.in/content/addition-silyl-ketene-acetal-alphabeta-unsaturated-cyclic-anhydrides-0