
TY  - JOUR
A1  - Bell, Stephanie E. V. 
A1  - Brown, Roger F. C. 
A1  - Eastwood, Frank W. 
A1  - Horvath, Julianna M. 
T1  - An Approach to Some Spiro Oxindole Alkaloids Through Cycloaddition Reactions of 3-Methylideneindolin-2-one
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 2000
VL  - 53
IS  - 3
SP  - 183
EP  - 190
KW  - Carbamate; flash vacuum pyrolysis; indole; synthesis; ylide.
UR  - https://doi.org/10.1071/CH00016 
N2  - 3-Methylideneindolin-2-one (3-methylideneoxindole) (1) was prepared in 60&#8211;89% yield by flash vacuum pyrolysis of the acetate or methyl carbonate of 3-hydroxy-3-methylindolin-2-one, and was fully characterized, but application of the same procedure to 3-hydroxy-5-methoxyindolin-2-one did not give useful yields. Cycloaddition reactions of CH2= +NR&#8211;CH2 &#8211; and of the related ylide (25) (from 1-(trimethylsilylmethyl)piperidine-2-carbonitrile and AgF) to 3-methylideneindolin-2-one (1) gave 4&#8211;20% yields of spiro oxindoles, but yields were markedly below those achieved in cycloadditions to the more electrophilic N-phenylmaleimide (70&#8211;79%). Attempted alkylation of weakly basic secondary amines, e.g. piperidine-2-carbonitrile, with Me3SiCH2Cl in dimethyl sulfoxide/K2CO3 gave only carbamates Me3SiCH2OOCNR2. 
ER  -

