igo A GENERAL REVIEW OF 



been made by Purdie and Neave (57). The preparation of 

 the methyl ester is readily accomplished by allowing methyl 

 malate (1 mol.), silver oxide (2 mols.), and methyl iodide 

 (4 mols.) to react spontaneously, completing the reaction by 

 two hours' heating over a steam-bath, and finally extracting 

 the product with boiling ether. After removal of the solvent 

 the residual oil is dried and distilled under reduced pressure. 

 Methyl Z-methoxysuccinate is obtained in a chemically pure 

 form after four such distillations, and its optical rotation is 

 unchanged by further distillation. In a similar manner ethyl 

 Z-methoxysuccinate was prepared from ethyl malate, while 

 the propyl ester was prepared by the interaction of silver 

 7-methoxysuccinate and propyl iodide. From the methyl 

 ester the active diamide and dianilide of Z-methoxysuccinic 

 acid were prepared by standard methods and their optical 

 activity determined. The data so obtained form a useful 

 addition to that which has already been gathered. 



This work has been further extended by Purdie and the 

 writer (58). By the action of phosphorus pentachloride, 

 Z-methoxysuccinic acid was converted into the corresponding 

 acid chloride, no racemisation or inversion occurring during 

 the reaction. By boiling the same acid with acetyl chloride, 

 Z-methoxy-succinic anhydride was prepared as an active liquid. 

 One of the two possible isomeric methyl hydrogen Z-methoxy 

 succinates was obtained when this anhydride was dissolved 

 in methyl alcohol, and the work further included the prepara- 

 tion of Z-methoxysuccinamic acid. 



The behaviour of methyl Z-methoxysuccinate with the two 

 Grignard reagents, magnesium methyl iodide and magnesium 

 phenyl bromide, presents an interesting comparison. By inter- 

 action with the former, the active ditertiary glycol y-methoxy- 

 /3e-dimethylhexane-/3e-diol HO . CMe 2 . CHOMe . CH 2 . CMe 2 OH, 

 is produced and isolated in the form of its anhydride 

 (Purdie and Arup (59) ). During the reaction of the ester 

 with magnesium phenyl bromide, however, the elements of 



