A Route to Carbasugar Analogues - Jonathan Clayden - The ...

Experimental for chapter 4.2
Synthesis of (1R,2S,3S,4S,5R,6S)-6-isopropyl-5-methyl-5-(N-methyl-(4R,5R)-4,5-
diphenyloxazolidin-2-yl)cyclohexane-1,2,3,4-tetraol (311)
Ph Ph
Ph Ph Ph Ph Ph Ph
O
N
O
NMe
O
NMe
O
NMe
1
OsO 4
HO 6
HO
2
OH
CH 2 Cl 2 , NMO
5
HO
3
4 OH
OH HO OH
OH
OH
O
O
311 318 319
General procedure 5 was employed using olefin 310 (20 mg, 0.05 mmol), OsO 4 (12 µl,
2.0 mol%), NMO (12 mg, 0.10 mmol), in CH 2 Cl 2 (0.5 cm 3 ). Upon complete reaction
of starting material (7 days), sodium metabisulfite (0.2 cm 3 , 5% w/w aq. solution) was
added. Purification by flash chromatography (19:1 to 1:2 petrol:EtOAc) yielded
tetraol 311 (4 mg, 21%), enone 318 (2 mg, 11%) and triol 319 (8 mg, 42%) as
colourless oils.
311 R f : 0.23 (2:1, petrol:EtOAc); [α] 20 D : +14 (c = 1, CHCl 3 ); MS m/z (ES–) 442
(100%, MH + ), 443 (31%, (M+1)H + ); HRMS: found 442.2584, MH requires 442.2588;
IR ν max (film)/cm⎯¹ 3398 (br, O-H), 2927 (m, C-H), 2360 (w), 1457 (w), 1065; ¹H-
NMR (CDCl 3 , 500 MHz) δ 7.33-7.27 (m, 6H, Ph), 7.22-7.16 (m, 2H, Ph), 7.08-6.99
(m, 2H, Ph), 4.63 (d, 1H, J 9.0, CHOPh), 4.59 (d, 1H, J 3.0, H6), 4.51 (s, 1H, CHNO),
4.15 (dd, 1H, J 11.0, 9.0, H3), 3.95-3.90 (m, 1H, H5), 3.71 (t, 1H, J 9.0, H4), 3.35 (d,
1H, J 9.0, CHNPh), 2.29 (s, 3H, NMe), 2.13 (p, 1H, J 7.0, CHMe 2 ), 1.74 (d, 1H, J
11.0, H2), 1.29 (d, 3H, J 7.0, CHMe A Me b ), 1.28 (s, Me), 1.20 (d, 3H, J 7.0,
CHMe a Me B ); ¹³C-NMR (CDCl 3 , 75.5 MHz) δ 139.2 (ipso-Ph), 137.1 (ipso-Ph),
128.544, 128.3, 128.0, 127.7, 126.3 (Ph), 101.2 (CHNO), 85.2 (CHOPh), 79.7
(CHNPh), 76.8 (CHOH), 73.6 (CHOH), 73.5 (CHOH), 72.6 (CHOH), 52.2 (C2), 47.2
(C1), 39.7 (NMe), 27.7 (CHMe a Me B ), 25.3 (CHMe 2 ), 23.144 (Me), 18.2 (CHMe A Me b ).
318 R f : 0.20 (9:1, petrol:EtOAc); [α] 24 D : +268 (c = 1, CHCl3); MS m/z (ES+) 428
(100%, MNa + ), 429 (32%, (M+1)H + ); HRMS: found 428.2191, MNa requires
428.2196; IR ν max (film)/cm⎯¹ 3383 (m, O-H), 2947 (m, C-H), 2355 (m), 1675 (C=O),
1450 (w, C-Me), 1061 (m); ¹H-NMR (CDCl 3 , 500 MHz) δ 7.34-7.29 (m, 4H, Ph, H6),
7.27-7.23 (m, 3H, Ph), 7.18-7.15 (m, 2H, Ph), 7.03-6.99 (m, 2H, Ph), 6.22 (d, 1H, J
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