Rf = 0 . 40 ( 2 : 3 EtOAc / hexane ) ; 1 H - NMR δ = 1 . 18 - 1 . 36 ( m , 6 H ) , 1 . 54 - 1 . 66 ( m , 12 H ) , 1 . 94 - 2 . 20 ( m , 8 H ) , 2 . 30 - 2 . 44 ( m , 1 H ) , 2 . 70 - 2 . 86 ( m , 1 H ) , 3 . 70 - 3 . 86 ( m , 1 H ) , 4 . 15 - 4 . 46 ( m , 8 H ) , 4 . 92 - 5 . 10 ( m , 2 H ) , 5 . 43 - 5 . 66 ( m , 2 H ) , 7 . 48 - 7 . 59 ( m , 2 H ) , 7 . 59 - 7 . 68 ( m , 1 H ) , 7 . 78 - 7 . 90 ( m , 2 H ) ppm ; IR ( neat ) ν = 3474 , 2982 , 2930 , 1737 , 1446 , 1372 , 1297 , 1178 , 1141 , 1081 , 1021 , 865 , 753 , 693 , 663 , 604 cm - 1 ; HRMS ( FAB ) calcd for C 34 H 45 Br 2 O 6 S [ C 34 H 49 Br 2 O 8 S - 2 H 2 O ] 739 . 1304 , found 739 . 1310 .