(14) L. J. Altman and B. W. Neton, J. Am. Chem. Soc., 91, 6183 (1989). (16) Structurea 6 and 10 were fully supported by additional NMR, IR, and CIMS data. (16) In the reduction of certain 8-halopenicillinate8, hydrogen is transferred from the 1- hindered side of the substrata (e) JA Aimetti, ES Hamanaka, D. A. Johnson, and M. 9. Xellogg, Tetrahedron Lett., 4361 (1979); (b) P. J. Giddinps, D. I. John, and E. J. Thomae, ibid., 21, 399 11990). ___~ (17) B. Ganem, ...