
TY  - JOUR
A1  - Amiet, RG 
A1  - Eastwood, FW 
A1  - Rae, ID 
T1  - Tetronic acid derivatives: Synthesis of an indolone-spiro-hydroxytetronimide
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1972
VL  - 25
IS  - 7
SP  - 1473
EP  - 1481
KW  - 
UR  - https://doi.org/10.1071/CH9721473 
N2  - The synthesis of l-methylindol-2(3H)-one-3-spiro-2'-3',4'-dihydroxy5'-imino-2',5'-dihydrofuran (4; R1 = R2 H) is described. The compound is readily oxidized to yield 1-methylindole-2,3-dione and 2-oxomalonamic acid, which was isolated as the phenylhydrazone, and on acetylation it forms a mono- or di-acetate. It reacts with phenylhydrazine with opening of the tetronimide ring to form 3-(2',3'-dihydro-l'-methyl-2'-oxoindo1-3'-yl)-3-oxo-2-phenylhydrazonopropanamide (5). The latter compound can be cyclized to yield a new pyranoindole (6). 
ER  -

