698 WL Mitchell, ML Hill, RF Newton, P. Ravenscroft and DI С Scopes Vol. 21 presence of EEDQ, afforded the hydrazide 12. Treatment of 12 with hydrogen bromide in 2-methoxyethanol, at re- flux, caused ring closure to 13. Subsequent hydrogenolysis of the benzyl protecting group provided the acyclovir iso- stere 3 which showed the expected [6] spectral properties ('H nmr, uv and ir). Alternatively, thermal cyclization of 14 gave 15 which was ...
[Ashton, Peter R.; Hoerner, Bernd; Kocian, Oldrich; Menzer, Stephan; White, Andrew J. P.; Stoddart, J. Fraser; Williams, David J. Synthesis, 1996 , # 8 p. 930 - 940]