Page 1. Tetrahedron Letters,Vol.29,No.35,pp 4431-4434,1988 0040-4039/88.$3.00 + .OO Printed in Great Britain Pergamon Press plc Page 2. 4432 ... Chem., 2, 774(1967). 5) C. Srinivasan, A. Shunmugasundarum, and N. Arumugam, J. Chem. Sot., Perkin Trans. II, 17(1985). 6) 0. S. Lee