(5 ml) was added, and the mixture partitioned between Et2O (40
ml) and brine (10 ml). Usual work-up (Et2O, Na2SO4) followed
by column chromatography (23 : 2 petrol : EtOAc ϩ 1% Et3N)
gave the title compound (100 mg, 58%) as a colourless oil: Rf
0.31 (23 : 2 petrol : EtOAc); νmax(film)/cmϪ1 2982(m), 2935(m),
1732(s), 1663(s), 1634(s), 1604(w), 1454(m), 1268(s), 1146(s),
700(m); δH(400 MHz; CDCl3) 1.17 (3H, t, J 7.1, OCH2CH3),
1.43 (6H, s, C(CH3)2), 1.88 (3H, s, C(CH3)CO), 3.54 (2H, d,
J 7.0, PhCH2), 4.15 (2H, q, J 7.1, OCH2CH3), 6.19 (1H, dt,
J 15.0 and 7.0, H-7), 6.44 (1H, dd, J 15.0 and 10.7, H-6), 6.82
(1H, d, J 10.7, H-5), 7.16–7.35 (5H, m, ArH); δC(100.6 MHz;
CDCl3) 12.7 (OCH2CH3), 14.0 (C(CH3)CO), 24.4 (C(CH3)2),
39.6 (PhCH2), 52.6 (C(CH3)2), 61.1 (OCH2CH3), 126.4 (C-7),
127.1 (ortho-CH), 128.6 (para-CH), 128.6 (meta-CH), 132.5
(ipso-C), 138.2 (C-6), 138.9 (C-4), 141.8 (C-5), 175.4 (ester-CO),
199.3 (ketone-CO); m/z (APCI) 301 (60%, MHϩ), 91 (100),
71 (70); HRMS: Found 301.1801 (MHϩ). C19H25O3 requires
301.1803.
Ethyl 3-oxo-10-phenyl-2,2,4-trimethyldeca-(4E,6E,8E )-
trienoate 26a
To a stirred solution of bis(acetonitrile)dichloropalladium()
(8 mg, 0.03 mmol) in dry, degassed DMF (3 ml) was added a
solution of iodide 25 (188 mg, 0.77 mmol) in dry DMF (1 ml),
followed by a solution of stannane 22 (442 mg, 0.89 mmol) in
dry DMF (1 ml) at RT. After 5.5 hours the mixture was diluted
with Et2O (50 ml), washed with aq. KF (2 × 20 ml) then brine
(20 ml). The combined aqueous layers were back-extracted with
EtOAc (3 × 20 ml), then the combined organic layers were dried
(MgSO4), filtered and concentrated in vacuo. Purification by
column chromatography (47 : 3 petrol : EtOAc) gave the title
compound (211 mg, 84%) as a pale yellow oil: Rf 0.31 (23 : 2
petrol : EtOAc); νmax(film)/cmϪ1 2934(m), 1731(s), 1660(s),
1607(s), 1264(s), 1149(s), 993(m); δH(400 MHz; CDCl3) 1.17
(3H, t, J 7.1, OCH2CH3), 1.45 (6H, s, C(CH3)2), 1.92 (3H, s,
C(CH3)CO), 3.48 (2H, d, J 6.8, PhCH2), 4.14 (2H, q, J 7.1,
OCH2CH3), 6.07 (1H, dt, J 15.0 and 7.1, H-9), 6.20 (1H, dd,
J 15.0 and 9.8, H-8), 6.47 (2H, m, H-6 and H-7), 6.83 (1H, d,
J 10.1, H-5), 7.17–7.34 (5H, m, ArH); δC(100.6 MHz; CDCl3)
13.4 (OCH2CH3), 13.6 (C(CH3)CO), 24.3 (C(CH3)2), 39.1
(PhCH2), 52.6 (C-2), 61.1 (OCH2CH3), 126.5 (para-CH), 126.8
(meta-CH), 127.1 (ipso-C), 128.5 (C-6), 128.7 (C-7), 129.0
(ortho-CH), 131.4 (C-5), 133.2 (C-8), 138.1 (C-4), 138.7 (C-9),
175.8 (ester-CO), 199.2 (ketone-CO); m/z (APCI) 327 (17%,
MHϩ), 211 (23), 155 (29), 143 (100), 115 (33).
Ethyl 3-hydroxy-8-phenyl-2,2,4-trimethylocta-(4E,6E )-dienoate
24
NaBH4 (12 mg, 0.32 mmol) was added to a stirred solution of
ketone 23 (32 mg, 0.11 mmol) in MeOH (3 ml) at 0 ЊC. After
1 hour at the same temperature another portion of NaBH4
(8 mg, 0.21 mmol, 2.0 equiv.) was added, and stirring continued
for a further hour. Sat. aq. NH4Cl (3 ml) was added, and the
mixture partitioned between Et2O (40 ml) and brine (5 ml).
Usual work-up (Et2O, Na2SO4), followed by column chromato-
graphy (21 : 4 petrol : EtOAc ϩ 1% Et3N) gave the title com-
pound (24 mg, 74%) as a colourless oil: Rf 0.24 (21 : 4 petrol :
EtOAc); νmax(CHCl3)/cmϪ1 3560(br s), 2983(s), 2928(s), 1722(s),
1698(m), 1602(w), 1453(m), 1252(s), 1142(s), 743(s); δH(400
MHz; CDCl3) 1.15 (3H, s, CH3), 1.22 (3H, s, CH3), 1.29 (3H, t,
Ethyl 3-hydroxy-10-phenyl-2,2,4-trimethyldeca-(4E,6E,8E )-
trienoate 26b
To a stirred solution of ketone 26a (62 mg, 0.19 mmol) in EtOH
(4 ml) was added NaBH4 (29 mg, 0.77 mmol) at 0 ЊC. The
mixture was then stirred at RT for 2 hours, before another por-
tion of NaBH4 (22 mg, 58 mmol) was added. After a further
8 hours sat. aq. NH4Cl (4 ml) was added, and the mixture par-
titioned between Et2O (40 ml) and 1 M HCl (10 ml). Usual
work-up followed by column chromatography (45 : 5 petrol :
EtOAc) gave the title compound (58 mg, 92%) as a colourless
oil: Rf 0.19 (23 : 2 petrol : EtOAc); λmax(MeOH)/nm 269 (ε/dm3
molϪ1 cmϪ1 24030), 278 (31190), 287 (24440); νmax(film)/cmϪ1
3490(br s), 2981(m), 1719(s), 1453(m), 1253(s), 1131(s), 989(s),
699(s); δH(400 MHz; CDCl3) 1.18 (3H, s, CH3), 1.22 (3H, s,
CH3), 1.20 (3H, t, J 7.1, OCH2CH3), 1.75 (3H, s, C(CH3)COH),
3.21 (1H, d, J 6.0, OH), 3.46 (2H, d, J 7.2, PhCH2), 4.11 (2H, q,
J 7.1, OCH2CH3), 4.12 (1H, d, J 6.0, CH(OH)), 5.87 (1H, dt,
J 7.2, 14.4, H-9), 6.03 (1H, d, J 11.1, H-5), 6.21 (2H, m, H-7 and
H-8), 6.37 (1H, dd, J 14.1 and 11.1, H-6), 7.18–7.32 (5H,
m, ArH); δC(100.6 MHz; CDCl3) 13.9 (C(CH3)CHOH), 14.1
(OCH2CH3), 23.8 (CH3), 20.8 (CH3), 39.1 (PhCH2), 46.8
(C-2), 60.9 (OCH2CH3), 82.3 (C-3), 126.0 (ortho-CH), 126.1
(para-CH), 126.8 (C-6), 127.0 (meta-CH), 128.0 (C-5), 128.4
(C-9), 128.5 (ipso-C), 133.0 (C-8), 133.3 (C-7), 140.1 (C-4),
177.8 (CO); m/z (APCI) 329 (4%, MHϩ), 283 (15), 213 (100),
143 (43), 116 (32). HRMS: Found 329.4569 (MHϩ). C21H29O3
requires 329.4571.
J 7.1, OCH CH ), 1.73 (3H, s, CH᎐C(CH )), 3.17 (1H, br s, OH),
᎐
2
3
3
3.45 (2H, d, J 7.0, PhCH2), 4.13 (1H, d, J 6.6, H-3), 4.15 (2H, q,
J 7.1, OCH2CH3), 5.82 (1H, dt, J 15.0 and 7.0, H-7), 5.99 (1H, d,
J 10.8, H-5), 6.33 (1H, dd, J 15.0 and 10.8, H-6), 7.18–7.34 (5H,
m, ArH); δC(100.6 MHz; CDCl3) 13.7 (CH3), 14.1 (CH3), 20.8
(OCH CH ), 23.9 (CH᎐C(CH )), 39.3 (PhCH ), 46.5 (C-2), 60.9
᎐
2
3
3
2
(OCH2CH3), 82.4 (C-3), 126.1 (C-7), 126.9 (para-CH), 128.4
(C-6), 128.5 (meta-CH), 128.5 (ortho-CH), 133.4 (C-5), 134.9
(ipso-C), 140.2 (C-4), 177.9 (CO); m/z (GCMS) 302 (2%, MHϩ),
285 (35, [M Ϫ OH]ϩ), 204 (32), 187 (100); HRMS: Found
320.2219 (NH4ϩ). C19H27O3 requires 320.2226.
(E )-1-Iodo-3-phenylpropene 25
To a stirred suspension of CrCl2 (568 mg, 462 mmol) in dry
THF (20 ml) was added a solution of iodoform (606 mg, 1.54
mmol) and freshly distilled phenylacetaldehyde (93 mg, 0.77
mmol) in dry THF (7 ml) over 5 minutes at 0 ЊC. The mixture
was stirred at 0 ЊC for 1 hour then at RT for 2 hours, before
being poured into water (50 ml). The layers were separated, and
the aqueous layer extracted with EtOAc (4 × 20 ml). The com-
bined organic layers were washed with sat. aq. Na2S2O3 (25 ml),
brine (25 ml), dried (Na2SO4), filtered and concentrated in
vacuo. Purification by column chromatography (hexane) gave
1,1-Dibromo-5-phenylpenta-(1Z,3E )-diene 29
1
the title compound (188 mg, 79%, 10 : 1 (E) : (Z)-ratio by H
NMR) as a colourless oil: Rf 0.34 (hexane); νmax(film)/cmϪ1
3025(m), 1605(m), 1495(s), 1452(s), 1219(m), 951(s), 747(s),
697(s); δH(400 MHz; CDCl3) (E)-isomer: 3.38 (2H, dd, J 7.0
and 0.9, PhCH2), 6.08 (1H, dt, J 14.4 and 1.0, H-1), 6.67 (1H,
dt, J 14.4 and 7.0, H-2), 7.14–7.33 (5H, m, ArH); (Z)-isomer:
3.52 (1H, d, J 5.3, PhCH2), 6.37–6.50 (2H, m, H-1 and H-2);
δC(50.3 MHz; CDCl3) (E)-isomer 42.2 (PhCH2), 76.6 (C-1),
126.9 (para-CH), 128.9 (ortho-CH), 129.0 (meta-CH), 138.3
(ipso-C), 145.1 (C-2); (Z)-isomer: 41.0 (PhCH2), 83.8 (C-1),
126.8 (para-CH), 128.9 (meta-CH), 129.0 (ortho-CH), 138.8
(ipso-C), 140.3 (C-2); m/z (APCI) 245 (4%, MHϩ), 117 (100);
HRMS: Found 243.1388 (MHϩ). C9H10I requires 243.1385.
PPh3 (1.22 g, 4.66 mmol) was added portionwise over 1 minute
to a stirred solution of CBr4 (0.77 g, 2.33 mmol) in dry DCM
(10 ml) at 0 ЊC. After 3 minutes a solution of aldehyde 4 (0.31 g,
2.12 mmol) in dry DCM (2 ml) was added dropwise over
3 minutes to the reaction mixture. The solution was stirred at
0 ЊC for 3 hours, then washed with water (10 ml), sat. aq. Na2-
S2O3 (10 ml), dried (MgSO4), filtered and concentrated. Purifi-
cation by column chromatography (hexane) gave the title
compound (0.56 g, 84%) as an orange oil: Rf 0.39 (hexane);
νmax(film)/cmϪ1 3027(m), 1765(m), 1602(w), 1495(m), 1453(m),
1235(w), 967(s), 803(s), 748(s), 698(s); δH(400 MHz; CDCl3)
3.45 (2H, d, J 6.5, PhCH2), 6.04 (1H, dt, J 15.1 and 6.5, H-4),
O r g . B i o m o l . C h e m . , 2 0 0 3 , 1, 3 7 2 6 – 3 7 3 7
3734