A solution of (3R,3aR,6S,6aS)-6-(methylthio)hexahydro-2H-furo[3,2-b]pyrrol-3-ol in 1,4-dioxane (5 mL) was added whilst stirring to a solution of sodium carbonate (123 mg, 1.16 mmol) in water (1.5 mL) at 0° C. A solution of 9-fluorenylmethoxycarbonyl chloride (150 mg, 0.58 mmol) in 1,4-dioxane (1.5 mL) was added dropwise over 5 minutes then the mixture allowed to warm to ambient temperature over 2 hours. Water (20 mL) was added and the product extracted into dichloromethane (3×10 mL). The organic layer was dried (Na2SO4), filtered and reduced in vacuo to leave a residue. Flash chromatography over silica, eluting with diethyl ether:pentane mixtures 2:1 gave alcohol (55) as a white solid (130 mg, 60%). TLC (Rf=0.19, Et2O:pentane 2:1); HPLC-MS 398.2 [M+H]+, 420.1 [M+Na]+, 817.3 [2M+H]+; analytical HPLC single main peak, Rt=16.096 min., [α]D17 −59.4° (c=2.78, CHCl3); δH (500 MHz, CDCl3) mixture of rotamers major:minor 4:3; 1.06 (0.57H, d, J=3.63 Hz, OH major), 2.04 (1.71H, s, SCH3 major), 2.14 (1.29H, s, SCH3 minor), 2.57 (0.43H, d, J=2.83 Hz, OH minor), 3.10 (0.57H, d, J=5.40 Hz, FmocNCH2 major), 3.21-3.24 (0.43H, m, FmocNCH2 minor), 3.41 (0.57H, dd, J=12.18 and 5.57 Hz, OCH2CHOH major), 3.52-3.82 (4.43H, m, FmocNCH, CHSCH3 OCH2CHOH minor, 1×FmocNCH2 and 1 ×OCH2CHOH), 3.92 (0.43H, dd, J=9.85 and 4.41 Hz, OCH2CHOH minor), 4.23-4.84 (4.57H, m, Fmoc CH, OCHCHSCH3, Fmoc CH2 minor and 1×OCH2CHOH major), 7.28-7.80 (8H, Fmoc aromatic CH); δC (125 MHz, CDCl3) 14.574/14.768 (SCH3), 47.234, 47.445, 48.069 and 48.826 (Fmoc CH and CHSCH3), 50.417/50.633 (FmocNCH2), 65.752/67.282 (Fmoc CH2), 68.555/69.282 (FmocNCH), 74.361/74.600 (OCH2CHOH), 75.774/76.148 (OCH2CHOH), 85.505/86.026 (OCHCHOCH3), 119.848, 120.003, 120.029, 124.512, 124.593, 124.946, 127.030, 127.063, 127.427, 127.507, 127.755, 127.771 and 127.892 (Fmoc aromatic CH), 141.196, 141.320, 141.378, 141.428, 143.581, 143.818, 143.890 and 143.964 (Fmoc quaternary), 154.115/154.849 (Fmoc C═O).
