The anhydrides, I, were prepared according to the general procedure of Allen, et aL5 These condensed with p-nitrobenzaldehyde in the presence of the sodium salt of the corresponding acid to give I1 in yields varying from 2540%. In one preparation (R= i-amyl) we employed triethylamine in place of sodium isoheptanoate and secured the acid I1 (R= i- amyl) in 52% yield. In contrast to the aromatic series in no instance were we able to isolate ...
