(a) NaBH3CN, AcOH, 0°C–r.t.; (b) (i) benzenesulfonyl chloride, pyridine, reflux; (ii) LiAlH4, THF, 0°C–r.t.; (iii) pyridinium dichromate (PDC), molecular sieves, CH2Cl2, r.t.; (c) (i) methyl(triphenylphosphorylidene)acetate, CH2Cl2, r.t.; (ii) 1 M LiOH(aq), dioxane, 40°C; (d) (i) NH2OTHP, PYBOP, Et3N, DMF, r.t.; (iii) trifluoroacetic acid, CH3OH, r.t. Abbreviations: NaBH3CN, sodium cyanoborohydride; AcOH, acetyl acid; LiAlH4 (LAH), lithium aluminium hydride; THF, tetrahydrofuran; PDC, pyridinium dichromate; NH2OTHP, O-(tetrahydro-2H-pyran-2-yl)hydroxylamine; PYBOP, benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate; Et3N, triethylamine; DMF, dimethylformamide; TFA, trifluoroacetic acid.