04.11.2014 Views

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

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

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

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

Experimental for chapter 4.1<br />

291 R f : 0.11 (4:1, petrol:EtOAc); [α] 27 D : +89 (c = 1.2, CHCl 3 ); MS m/z (ES+) 520<br />

(100%, MNa + ), 521 (34%, (M+1)Na + ), 498 (75%, MH + ); HRMS: found 498.2632,<br />

MH requires 498.2639; IR ν max (film)/cm⎯¹ 3333 (br, O-H), 2954 (C-H), 1638, 1453,<br />

1076; ¹H-NMR (CDCl 3 , 500 MHz) δ 7.35-7.15 (m, 15H, Ph), 5.19 (d, 1H, J 9.0,<br />

CHOPh), 5.05 (d, 1H, J 9.0, CHNPh), 4.78 (d, 1H, J 11.5, OBn), 4.63 (d, 1H, J 11.5,<br />

OBn), 4.15-4.09 (m, 1H, H3), 3.63 (dd, 1H, J 8.0, 1.0, H4), 3.38 (dd, 1H, J 4.0, 1.0,<br />

H5), 3.21 (d, 1H, J 4.0, H6), 2.28 (s, 1H), 2.17 (d, 1H, J 2.0, C3OH), 1.90 (pd, 1H, J<br />

7.0, 1.0, CHMe 2 ), 1.50 (s, 3H), 1.36 (dd, 1H, J 11.0, 1, H2), 1.01 (d, 3H, J 7.0, i-Pr),<br />

0.94 (d, 3H, J 7.0, i-Pr); ¹³C-NMR (CDCl 3 , 75.5 MHz) δ 169.3 (C=N), 141.7 (ipso-<br />

Ph), 139.2 (ipso-Ph), 138.0 (ipso-Ph), 129.0, 128.7, 128.7, 128.6, 128.5, 128.2, 127.9,<br />

127.6, 126.9 (Ph), 89.8 (CHOPh), 83.0, 77.5, 71.9, 69.1, 60.4, 53.4, 53.0, 42.7, 29.2,<br />

26.9, 25.7, 18.7.<br />

Synthesis of (1S,2S,3R,4S,5R,6R)-5,6-bis(benzyloxy)-3-((4R,5R)-4,5-<br />

diphenyloxazolin-2-yl)-4-isopropyl-3-methylcyclohexane-1,2-diol (300)<br />

Ph Ph<br />

Ph Ph<br />

O<br />

N<br />

O<br />

N<br />

OsO 4 , NMO, CH 2 Cl 2<br />

HO<br />

6<br />

1<br />

2<br />

OBn<br />

OBn<br />

HO<br />

5<br />

3<br />

4 OBn<br />

OBn<br />

General procedure 5 was employed using olefin 289 (26 mg, 0.04 mmol), OsO 4 (0.2<br />

mg, 2 mol %), NMO (12 mg, 0.1 mmol), in CH 2 Cl 2 (0.5 cm 3 ). Upon complete<br />

reaction of starting material (c. 9 d), sodium metabisulfite (0.1 cm 3 , 5% w/w aq.<br />

solution) was added. Purification by flash chroma<strong>to</strong>graphy (10% EtOAc in petrol)<br />

yielded diol 300 (26 mg, 96 %) as a colourless oil.<br />

R f : 0.09 (4:1, petrol:EtOAc); [α] 26 D : +35 (c = 1.2, CHCl 3 ); MS m/z (ES+) 606.4<br />

(100%, MH + ), 607.4 (48%, (M+1)H + ), 628.4 (46%, MNa + ); HRMS: found 606.3222,<br />

MH requires 606.3214; IR ν max (film)/cm⎯¹ 3441 (br, OH), 2948 (m, C-H), 1642<br />

(C=N), 1453, 1069; ¹H-NMR (CDCl 3 , 500 MHz) δ 7.37-7.18 (m, 16H, Ph), 7.16-7.08<br />

(m, 4H, Ph), 5.09-5.06 (m, CHOPh, OBn), 4.99 (d, J 9.0, CHNPh), 4.82 (d, J 11.5,<br />

OBn'), 4.66 ("t", 2H, J 11.5, OBn, OBn'), 4.29 (dd, 1H, J 10.0, 3.0, H5), 4.09 (dd, 1H,<br />

J 11.0, 9.0, H3), 4.00 (d, 1H, J 3, H6), 3.88-3.82 (m, 1H, H4), 2.62 (br s, 1H, OH),<br />

256

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!