After recooling to Ϫ78 ЊC a solution of the crude aldehyde in
THF (140 ml) was added and the reaction mixture was stirred
for 1 h. The reaction mixture was quenched by addition of
NH4Cl solution (20 ml), allowed to warm to rt and poured into
aqueous NH4Cl solution (400 ml). The aqueous phase was
extracted with Et2O (3 × 300 ml). The organic extracts were
washed with brine (150 ml), dried over MgSO4 and concen-
trated under reduced pressure. Purification of the residue by
flash column chromatography (silica gel, 10 to 50% Et2O in PE)
afforded the enone 7 (31.8 g, 83% over three steps) as a light
yellow liquid; [α]3D1 ϩ6.6 (c 1.00 in CHCl3) (Found: C, 72.4; H,
8.6. C20H28O4 requires C, 72.3; H, 8.5%); νmax(film)/cmϪ1 2984,
{[6.75 (dd, J 15.8, 6.3), 6.64 (dd, J 15.8, 5.9)] 1H, 1Ј-H}, {[6.45
(dd, J 15.8, 1.0), 6.43 (dd, J 15.8, 1.0)] 1H, 2Ј-H}, {[5.05 (ddd,
J 8.8, 5.9, 1.0), 4.55–4.44 (m)] 1H, 4-H}, {[4.79 (dq, J 9.1, 6.1),
4.27 (dq, J 8.8, 6.3)] 1H, 5-H}, 4.49 (2H, s, PhCH2), 3.55–3.43
(2H, m, 2 × 7Ј-H), 2.69–2.54 (2H, m, 2 × 4Ј-H), 1.85–1.55 (4H,
m, 2 × 5Ј-H, 2 × 6Ј-H), {[1.59 (d, J 6.3), 1.51 (d, J 6.1)] 3H,
5-CH3}; δC(50 MHz) [198.8, 198.6 (3Ј-C)], 138.4 (quat. Ph-C),
[136.8, 134.8, 132.9, 132.6 (1Ј-C, 2Ј-C)], 128.3 (Ph-C), 127.6
(Ph-C), 127.5 (Ph-C), [87.0, 83.7, 82.6, 79.0 (4-C, 5-C)], 72.9
(PhCH2), 69.8 (7Ј-C), [41.1, 40.7 (4Ј-C)], [29.0, 20.6, 20.5 (5Ј-C,
6Ј-C)], [18.0, 15.7 (5-CH3)]; m/z (FAB) 361 (MNaϩ, 10%), 339
(MHϩ, 68), 231 (Mϩ Ϫ Bn, 38) [Found (MHϩ) 339.1265.
C17H23O5S requires MH, 339.1266].
2933, 2866, 1698, 1678 (C᎐O), 1638 (C᎐C), 1454, 1379, 1240,
᎐
᎐
1173, 1105, 1036, 979, 858, 736, 698; δH(600 MHz) 7.34–7.22
(5H, m, 5 × Ph-H ), 6.67 (1H, dd, J 15.9, 5.8, 1Ј-H), 6.35 (1H,
dd, J 15.9, 1.0, 2-H), 4.46 (2H, s, PhCH2), 4.04 (1H, ddd, J 8.2,
5.8, 1.0, 4-H), 3.83–3.77 (1H, m, 5-H), 3.46 (2H, t, J 6.2, 2 ×
7Ј-H), 2.57 (2H, t, J 7.3, 2 × 4Ј-H), 1.74–1.67 (2H, m, 2 × 5Ј-H),
1.66–1.58 (2H, m, 2 × 6Ј-H), 1.43 (3H, s, 2-CH3), 1.40 (3H, s,
2-CH3), 1.28 (3H, d, J 6.1, 5-CH3); δC(150 MHz) 199.6 (3Ј-C),
140.9 (1Ј-C), 138.5 (quat. Ph-C), 130.5 (2Ј-C), 128.3 (Ph-C),
127.6 (Ph-C), 127.5 (Ph-C), 109.2 (2-C), 81.9 (4-C), 76.5 (5-C),
72.8 (PhCH2), 69.9 (7Ј-C), 40.4 (4Ј-C), 29.1 (6Ј-C), 27.3
(2-CH3), 26.7 (2-CH3), 20.7 (5Ј-C), 16.7 (5-CH3); m/z (EI) 332
(Mϩ, 1%), 214 (41), 185 (46), 172 (53), 169 (45), 127 (54), 111
(66), 97 (100), 91 (43) [Found (Mϩ) 332.1997. C20H28O4 requires
M, 332.1988].
[(4E,2S,3R)-2-(Carbonyloxy-ꢃC)-10-benzyloxy-6-oxo-(3,4,5-ꢄ)-
dec-4-en-3-yl]tricarbonyliron (10a) and [(4E,2S,3S)-2-
(carbonyloxy-ꢃC)-10-benzyloxy-6-oxo-(3,4,5-ꢄ)-dec-4-en-3-yl]-
tricarbonyliron (10b)
A solution of the cyclic sulfite 9 (5.37 g, 15.9 mmol) in degassed
PhH (300 ml) was added to Fe2(CO)9 (17.32 g, 47.6 mmol) and
the reaction mixture was submitted to sonication at rt for 5 h.
The mixture was filtered through a plug of Celite, washing the
residue with Et2O (1500 ml). After concentration of the filtrate
under reduced pressure the residue was purified by flash column
chromatography (silica gel, 1 to 70% Et2O in PE) affording a
1 : 1 mixture of the endo complex 10a and the exo complex 10b
(5.20 g, 74%). Separation of the diastereoisomeric complexes
was achieved using a Biotage FLASH 40i system (FLASH 40M
cartridge, 65% Et2O in PE) giving, in order of elution, the endo
complex 10a (2.46 g, 35%) as a bright yellow oil; [α]2D7 ϩ369.0
(c 1.00 in DCM); νmax(film)/cmϪ1 2934, 2860, 2088 (CO), 2023
(6E,8S,9S)-1-Benzyloxy-8,9-dihydroxydec-6-en-5-one (8)
AcOH (75 ml) and water (75 ml) were added to the acetonide 7
(15.0 g, 45 mmol) and the reaction mixture was stirred at 40 ЊC
for 20 h. The reaction mixture was carefully poured into an
aqueous NaHCO3 solution (300 ml) and solid NaHCO3 was
added until effervescence stopped. The mixture was extracted
with EtOAc (4 × 300 ml), the combined organic extracts were
washed with brine (100 ml), dried over MgSO4 and concen-
trated under reduced pressure. Purification of the residue by
flash column chromatography (75% EtOAc in PE to neat
EtOAc) afforded the diol 8 (12.1 g, 92%) as a colourless oil; [α]3D0
Ϫ10.6 (c 1.00 in CHCl3); νmax(film)/cmϪ1 3420 (OH), 2936, 2867,
(CO), 1675 (C᎐O), 1496, 1454, 1373, 1359, 1301, 1180, 1087,
᎐
1047, 996, 945, 831, 737, 697; δH(600 MHz) 7.38–7.24 (5H, m,
5 × Ph-H ), 5.53 (1H, dd, J 11.2, 8.6, 4-H), 5.04 (1H, dd, J 8.6,
4.6, 3-H), 4.56–4.47 (3H, m [incl. 4.50, 2H, s, PhCH2] 2-H,
PhCH2), 3.87 (1H, d, J 11.2, 5-H), 3.50 (2H, t, J 6.3, 2 × 10-H),
2.82–2.69 (2H, m, 2 × 7-H), 1.90–1.65 (4H, m, 2 × 8-H, 2 ×
9-H), 1.37 (3H, d, J 6.4, 3 × 1-H); δC(150 MHz) 207.9 (CO),
205.0 (CO), 203.9 (CO), 202.6 (CO), 199.7 (CO), 138.5 (quat.
Ph-C), 128.4 (Ph-C), 127.6 (2 × Ph-C), 92.0 (CH), 85.4 (CH),
73.0 (CH), 72.9 (PhCH2), 69.8 (10-C), 65.8 (CH), 43.0 (7-C),
29.1 (8-C or 9-C), 21.8 (1-C), 20.6 (9-C or 8-C); m/z (FIB)
443 (MHϩ, 75%), 386 (Mϩ Ϫ 2CO, 35), 358 (Mϩ Ϫ 3CO, 32),
331 (MHϩ Ϫ 4CO, 100), 239 (Mϩ Ϫ 4CO Ϫ Bn, 13), 223 (45)
[Found (MHϩ) 443.0785. C21H23FeO7 requires MH, 443.0793];
and the exo complex 10b (2.46 g, 35%) as a bright yellow oil;
[α]2D7 Ϫ339.5 (c 1.00 in DCM); νmax(film)/cmϪ1 3033, 2933, 2861,
1654 (C᎐O), 1638 (C᎐C), 1558, 1540, 1507, 1496, 1456, 1365,
᎐
᎐
1319, 1154, 1076, 986; δH(400 MHz) 7.37–7.24 (5H, m, 5 ×
Ph-H ), 6.75 (1H, dd, J 15.9, 5.1, 7-H), 6.38 (1H, dd, J 15.9, 1.4,
6-H), 4.48 (2H, s, PhCH2), 4.06–3.98 (1H, m, 8-H), 3.73–3.64
(1H, m, 9-H), 3.48 (2H, t, J 6.3, 2 × 1-H), 2.99 (1H, br s, OH ),
2.66 (1H, br s, OH ), 2.58 (2H, t, J 7.3, 2 × 4-H), 1.76–1.58 (4H,
m, 2 × 2-H, 2 × 3-H), 1.21 (3H, d, J 6.3, 3 × 10-H); δC(100
MHz) 200.3 (5-C), 144.2 (7-C), 138.4 (quat. Ph-C), 130.1 (6-C),
128.4 (Ph-C), 127.7 (Ph-C), 127.6 (Ph-C), 75.7 (8-C), 72.9
(PhCH2), 70.3 (9-C), 70.0 (1-C), 40.6 (4-C), 29.1 (2-C or 3-C),
20.8 (3-C or 2-C), 19.2 (10-C); m/z (EI) 293 (MHϩ, 11%), 185
(8), 168 (59), 91 (100) [Found (MHϩ) 293.1753. C17H25O4
requires MH, 293.1753].
2082 (CO), 2017 (CO), 1665 (C᎐O), 1496, 1453, 1305, 1120,
᎐
1104, 1049, 995, 946, 739, 695, 652, 603; δH(600 MHz) 7.37–
7.24 (5H, m, 5 × Ph-H ), 5.68 (1H, dd, J 11.0, 8.4, 4-H), 4.80
(1H, d, J 8.4, 3-H), 4.50 (2H, s, PhCH2), 4.27 (1H, q, J 6.5,
2-H), 3.72 (1H, d, J 11.0, 5-H), 3.50 (2H, t, J 6.4, 2 × 10-H),
2.79–2.66 (2H, m, 2 × 7-H), 1.85–1.63 (4H, m, 2 × 8-H, 2 ×
9-H), 1.42 (3H, d, J 6.5, 3 × 1-H); δC(150 MHz) 208.1 (CO),
204.9 (CO), 203.9 (CO), 202.5 (CO), 200.0 (CO), 138.5 (quat.
Ph-C), 128.3 (Ph-C), 127.6 (Ph-C), 127.5 (Ph-C), 93.6 (CH),
84.4 (CH), 72.9 (PhCH2), 70.7 (CH), 69.8 (10-C), 65.1 (CH),
42.9 (CH2), 29.1 (8-C or 9-C), 24.0 (1-C), 20.6 (9-C or 8-C); m/z
(1ЈE,2RS,4S,5S)-4-(7Ј-Benzyloxy-3Ј-oxohept-1Ј-en-1Ј-yl)-5-
methyl-1,3-dioxa-2-thiolane 2-oxide (9)
Freshly distilled SOCl2 (2.11 ml, 26.9 mmol) was added drop-
wise to a solution of the diol 8 (5.23 g, 17.9 mmol) and Et3N
(7.47 ml, 53.7 mmol) in Et2O (100 ml) at 0 ЊC. After 90 min the
reaction mixture was poured into aqueous NaHCO3 solution
(100 ml), the phases were separated and the aqueous phase was
extracted with Et2O (3 × 100 ml). The combined organic
extracts were washed with brine (40 ml), dried over MgSO4 and
concentrated under reduced pressure. Purification of the resi-
due by flash column chromatography (silica gel, 50% Et2O
in PE) afforded the cyclic sulfite 9 (5.37 g, 89%) as a yellow oil;
(1 : 1 mixture of diastereoisomers at sulfur); νmax(film)/cmϪ1
(FIB) 443 (MHϩ, 28%), 386 (Mϩ Ϫ 2CO, 13), 359 (MHϩ
Ϫ
3CO, 7), 331 (MHϩ Ϫ 4CO, 100), 239 (Mϩ Ϫ 4CO Ϫ Bn, 10),
223 (44) [Found (MHϩ) 443.0811. C21H23FeO7 requires MH,
443.0793].
General procedure for the preparation of alcohol complexes 11a
and 11b
For a 1.45 mmol scale reaction: AlnPr3 (1.0 M solution in
PhMe, 3.0 equiv.) was added dropwise to a solution of the
ketone complex (1.0 equiv.) in DCM (20 ml) at 0 ЊC. After 1 h
1 M aqueous HCl solution (10 ml) was added and the mixture
2933, 2847, 1677 (C᎐O), 1640 (C᎐C), 1451, 1358, 1209, 1100,
᎐
᎐
1046, 956, 867; δH(200 MHz) 7.40–7.22 (5H, m, 5 × Ph-H ),
J. Chem. Soc., Perkin Trans. 1, 2002, 874–882
877