A strategy allowing the straightforward synthesis of 1-C-phosphonomethyl and 1-C-phosphonodifluoromethyl iminosugars is reported. Conversion of sugar lactams to the corresponding imines with Schwartz′s reagent followed by their reaction with LiCH2P(O)(OEt)2 and LiCF2P(O)(OEt)2 stereoselectively afforded the 1,2-cis and 1,2-trans glycosyl phosphonates, resp., in modest to good yields. Application of this methodol. to C-2 orthogonally protected sugar lactams paved the way to 2-acetamido- and 2-deoxy-1-C-phosphonomethyl iminosugars.