F. Babudri et al. / Journal of Organometallic Chemistry 689 (2004) 326–331
329
yield, >99% e.e. determined by HPLC, hexane/2-pro-
panol 85/15, 0.5 ml/min). The residual solid was crys-
tallized from ethyl acetate/hexane (pale brown solid, mp
3.8. (1R,2R)-2-(benzoyloxy)-3-cyclohexyl-1-(cyclohexyl-
carbonyl)-3-oxopropyl benzoate (2g)
20
Compound 2g was prepared from 1 (0.396 g) in ac-
cordance with general procedure. Column chromatog-
raphy (60% petroleum ether/ethyl acetate) afforded
0.397 g of 2g (81% yield, >99% e.e. determined by
HPLC, hexane/2-propanol 98/2, 0.5 ml/min). The resi-
due was crystallized from hexane (white solid, mp 129–
187–189 °C), ½aꢂD ¼ ꢁ69:9° (c ¼ 0:5, CHCl3).
mmax (KBr) 3112, 1722, 1675, 1412, 1273, 1256, 1241,
1107, 1059, 754, 718, 710 cmꢁ1; dH (500 MHz, CDCl3)
8.04 (dd, J ¼ 3:9, 1.0 Hz, 2H), 8.01–7.97 (m, 4H), 7.71
(dd, J ¼ 4:9, 1.0 Hz, 2H), 7.58–7.52 (m, 2H), 7.43–7.37
(m, 4H), 7.17 (dd, J ¼ 4:9, 3.9 Hz, 2H), 6.66 (s, 2H); dC
(125.7 MHz, CDCl3) 185.2, 165.3, 140.5, 135.6, 133.9,
133.7, 130.0, 128.5, 74.8. Anal. Found: C, 63.60; H, 3.68;
S, 13.02. Calc. for C26H18O6S2: C, 63.66; H, 3.70; S
13.07%.
20
130 °C), ½aꢂD ¼ ꢁ107:2° (c ¼ 2:0, CHCl3).
mmax (KBr) 3065, 2928, 2854, 1743, 1723, 1601, 1451,
1289, 1260, 1247, 1108, 1097, 714, 705 cmꢁ1; dH (500
MHz, CDCl3) 8.06–8.01 (m, 4H), 7.61–7.55 (m, 2H),
7.45 (t like, J ¼ 7:8 Hz, 4H), 6.07 (s, 2H), 2.78–2.67 (m,
2H), 2.11–2.02 (m, 2H), 1.83–1.56 (m, 8H), 1.46–1.10
(m, 10H); dC (125.7 MHz, CDCl3) 205.9, 165.2, 133.7,
129.9, 128.6, 128.5, 75.4, 47.1, 29.0, 27.5, 25.7, 25.6,
25.2. Anal. Found: C, 73.50; H, 6.93. Calc. for
C30H34O6: C, 73.45; H, 6.99%.
3.6. (1R,2R)-2-(benzoyloxy)-1-decanoyl-3-oxododecyl
benzoate (2e)
Compound 2e was prepared from 1 (0.409 g) in ac-
cordance with general procedure. Purification by col-
umn chromatography (90% petroleum ether/ethyl
acetate) afforded 0.457 g of 2e as a pale yellow-orange
3.9. (1R,2R)-2-(benzoyloxy)-4,4-dimethyl-1-(2,2-dimeth-
ylpropanoyl)-3-oxopentyl benzoate (2h)
1
oil (76% yield, >98% e.e. determined by H-NMR shift
20
reagent experiment), ½aꢂD ¼ ꢁ48:4° (c ¼ 2:4, CHCl3).
Compound 2h was prepared from 1 (0.398 g) in ac-
cordance with general procedure. Purification by col-
umn chromatography (90% petroleum ether/ethyl
acetate) afforded 0.362 g of 2h (82% yield, >99% e.e.
determined by HPLC, hexane/2-propanol 98/2, 0.5 ml/
min). The residual solid was crystallized from hexane
mmax (neat) 3070, 2926, 2855, 1728, 1453, 1261, 1244,
1177, 1093, 1069, 1026, 712 cmꢁ1; dH (500 MHz, CDCl3)
8.09–8.03 (m, 4H), 7.63–7.57 (m, 2H), 7.46 (t like,
J ¼ 7:8 Hz, 4H), 5.92 (s, 2H), 2.66 (dt, J ¼ 17:7, 7.3 Hz,
2H), 2.52 (dt, J ¼ 17:7, 7.4 Hz, 2H), 1.61–1.50 (m, 4H),
1.28–1.09 (m, 24H), 0.83 (t, J ¼ 7:2 Hz, 6H); dC (125.7
MHz, CDCl3) 203.6, 165.3, 133.8, 129.9, 128.6, 128.5,
76.9, 39.1, 31.8, 29.3, 29.2, 29.0, 22.9, 22.6, 14.1. Anal.
Found: C, 74.69; H, 8.68. Calc. for C36H50O6: C, 74.71;
H, 8.71%.
20
(white solid, mp 126–128 °C), ½aꢂD ¼ þ21:2° (c ¼ 1:8,
CHCl3).
mmax (KBr) 3068, 2974, 2932, 2907, 2869, 1739, 1722,
1601, 1477, 1466, 1455, 1354, 1293, 1268, 1250, 1235,
1179, 1113, 1070, 1050, 1031, 974, 800, 715, 684 cmꢁ1
;
dH (500 MHz, CDCl3) 7.98–7.93 (m, 4H), 7.55–7.49 (m,
2H), 7.38 (t like, J ¼ 7:9 Hz, 4H), 6.39 (s, 2H), 1.25 (s,
18H); dC (125.7 MHz, CDCl3) 207.3, 165.1, 133.5, 129.9,
128.6, 128.4, 72.4, 44.1, 26.6. MS m=z 381 (Mþ-57, <1),
227 (4), 175 (3), 105 (100), 85 (4), 77 (19), 57 (43), 51 (5),
41 (15%). Anal. Found: C, 71.15; H, 6.92. Calc. for
C26H30O6: C, 71.21; H, 6.90%.
3.7. (1R,2R)-2-(benzoyloxy)-4-methyl-1-(2-methylprop-
anoyl)-3-oxopentyl benzoate (2f)
Compound 2f was prepared from 1 (0.399 g) in ac-
cordance with general procedure. Column chromatog-
raphy (80% petroleum ether/ethyl acetate) afforded
0.350 g of 2f (85% yield, >99% e.e. determined by
HPLC, hexane/2-propanol 98/2, 0.5 ml/min). The resi-
due was crystallized from hexane (white solid, mp 105–
3.9.1. General procedure for the synthesis of 2,3-O-
isopropylidene-1,4-diketones
20
106 °C), ½aꢂD ¼ ꢁ121:1° (c ¼ 2:0, CHCl3).
A THF solution (5 ml) of LiBr (0.551 g, 6.34 mmol)
was added at room temperature, under nitrogen, to a
stirred suspension of CuBr (0.454 g, 3.17 mmol) in THF
(5 ml). A freshly prepared THF solution of Grignard
reagent (3.17 mmol) and soon afterwards 2,3-O-iso-
mmax (KBr) 3068, 2975, 2934, 2874, 1735, 1724,
1713, 1601, 1466, 1454, 1318, 1277, 1238, 1179, 1111,
1094, 1070, 1026, 993, 715 cmꢁ1; dH (500 MHz,
CDCl3) 8.08–8.01 (m, 4H), 7.61–7.55 (m, 2H), 7.45 (t
like, J ¼ 7:8 Hz, 4H), 6.13 (s, 2H), 3.05–2.94 (m, 2H),
1.21 (d, J ¼ 7:2 Hz, 6H), 1.04 (d, J ¼ 6:7 Hz, 6H); dC
(125.7 MHz, CDCl3) 207.0, 165.2, 133.7, 129.9, 128.6,
75.5, 37.1, 18.6, 17.6; MS m=z 297 (2), 106 (8), 105
(100), 77 (17), 71 (7), 51 (4), 43 (36), 41 (5%). Anal.
Found: C, 70.20; H, 6.35. Calc. for C24H26O6: C,
70.23; H, 6.38%.
propylidene-L-tartaric acid dichloride 3 [16] (0.30 g, 1.32
mmol) in THF (15 ml) were quickly added to the stirred
solution of salts. The mixture was stirred at room tem-
perature for 10 min, quenched with aqueous NH4Cl and
extracted with ethyl acetate. The organic extracts were
dried over Na2SO4 and concentrated under vacuum.