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

Experimental for chapter 2
(CDCl 3 , 300 MHz) δ 8.00 (d, 1H, J 8.5, H6), 7.46-7.28 (m, 10H, Ph), 6.86-6.78 (m,
2H, H3, H5), 5.31 (d, 1H, J 7.5, CHO), 5.26 (d, 1H, J 7.5, CHN), 3.86 (s, 3H, OMe),
2.73 (s, 3H, CMe); 13 C-NMR (CDCl 3 , 125 MHz) δ 164.7 (C=N), 161.3 (C4), 142.5
(C2), 141.7 (ipso-Ph), 140.9 (ipso-Ph), 132.0, 128.9, 128.8, 128.3, 127.6, 126.6, 125.7,
119.2, 116.8, 110.9 (Ar), 87.8 (COPh), 79.3 (CNPh), 55.3 (OMe), 22.7 (Me).
Synthesis of (4R,5R)-2-((1S,6R)-6-sec-butyl-4-methoxy-1-methylcyclohexa-2,4-
dienyl)-4,5-diphenyloxazoline (102b’)
Ph
Ph
Ph
Ph
Ph
Ph
O
N
i) s-BuLi (3 eq), DMPU (6 eq)
-78 °C, 10 min
ii) MeI
O
1
6
5
N
7
2
3
4
8
9
10
11
+
O
N
OMe
OMe
dr 7:2
OMe
102b'
103b'
General procedure 2 was used employing oxazoline 101b (100 mg, 0.30 mmol) s-BuLi
(0.90 mmol in hexanes), DMPU (0.22 cm 3 , 36.4 mmol) and methyl iodide (0.1 cm 3 )
quench after 10 min. Flash chromatography (49:1 to 4:1 petrol:EtOAc) yielded
starting material (5 mg, 5%) and oxazolines 102b’ and 103b’ (94 mg, 78%, 9:1
mixture) as a clear oil.
R f : 0.29 (9:1, petrol:EtOAc); [α] 22 D : –104 (c = 1.0, CHCl 3 ); MS m/z (CI+) 402 (100%,
MH + ), 403 (27%, [(M+1)H] + ); HRMS: found 402.2431, MH requires 402.2428; IR
ν max (film)/cm⎯¹ 2959 (m), 1661 (C=N), 1452 (m), 1215, 1173 (m), 1086; ¹H-NMR
(major compound) (CDCl 3 , 500 MHz) δ 7.42-7.28 (m, 8H, Ph), 7.24-7.20 (m, 2H, Ph),
6.43 (d, 1H, J 10.0, H6), 5.74 (dd, 1H, J 10.0, 2.0, H5), 5.22 (d, 1H, J 8.5, CHOPh),
5.05 (d, 1H, J 8.5, CHNPh), 4.47 (dd, 1H, J 6.5, 2.0, H3), 3.61 (s, 3H, OMe), 2.73-
2.68 (m, 1H, H2), 1.71-1.64 (m, 1H, H9), 1.57 (s, 3H, H7), 1.42-1.32 (m, 1H, H10),
1.28-1.20 (m, 1H, H10’), 0.99 (d, 3H, J 6.5, H8), 0.95-0.90 (m, 3H, H11); ¹³C-NMR
(CDCl 3 , 125 MHz) δ 171.2 (C=N), 153.0 (C4), 141.9 (ipso-Ph), 140.4 (ipso-Ph), 135.1
(C5), 128.7, 128.7, 127.6, 126.7, 125.7 (Ph), 121.7 (C6), 89.0, 88.6 (CHOPh, C3), 78.9
(CHNPh), 54.2 (OMe), 44.8 (C2), 41.7 (C1), 39.0 (C9), 27.6 (C10), 25.8 (C7), 14.8,
12.4 (C8, C11).
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