References
- We greatfully acknowledge financial support of The Netherlands Foundation for Cancer Research Koningin Wilhelmina Fonds
- Odijk , W. M. , Wanner , M. J. , Koomen , G. J. and Pandit , U. K. 1978 . Heterocycles , 9 : 1403
- Koomen , G. J. , Alewijk , F. van , Blok , D. and Pandit , U. K. 1979 . Heterocycles , 12 : 1535
- Koomen , G. J. , Rhijn , J.B.M. van and Carels , R. Heterocycles , to be published