1. Private communication with Prof. S. F. Thames, Our thanks are due to Prof. Thames for informing us of their research result before publish.
2. T. Ogawa, M. Yasui and M. Matsui, in press.
3. Homogeneity of the product was examined by T. L. C. and was also shown by NMR spectral data. The reason of high stereoselectivity observed in this reaction, however, is not certain at the present time.