1. Lowman, O. E. Ber. 1888, 21, 784. (b) Claisen, L.
2. Zedel, W. Ber. 1891, 24, 140. (c) Hantzsch, A. Ber. 1891, 24, 495-506.
3. (a) Claisen, L; Lowman, O. E. Ber. 1888, 21, 784.
4. (b) Claisen, L.; Zedel, W. Ber. 1891, 24, 140.
5. (c) Hantzsch, A. Ber. 1891, 24, 495-506.