Synthesis and Spectroscopic Characterization of 1-13C- and 4-13C-Plastoquinone-9
FULL PAPER
2Ј-CH3), 5.11 [d, 3J(C-H) ϭ 4.8 Hz, 2 H, 1-OCH2O], 6.75 [d, 2J(C-
H) ϭ 3.4 Hz, 1 H, 6-CH] ppm. 13C NMR: δ ϭ 151.7 (1-13C) ppm.
[4-13C]-Plastoquinone-9 (1b): The above described procedure was
performed with 0.21 g (0.25 mmol) [4-13C]-1,4-di-O-bis(methoxy-
methyl)-1,4-dihydroxy-2,3-dimethyl-5-solanesylbenzene (2b) in 25
mL acetonitrile, 15 mL water, 0.50 g (2.99 mmol) 2,6-pyridinedicar-
boxylic acid and 1.50 g (2.75 mmol) ammonium cerium(VI) nitrate
to yield 0.21 g of crude product. After purification over silica 0.13 g
(69%, 72% from 4b) pure [4-13C]-plastoquinone-9 (1b) was ob-
[4-13C]-1,4-Di-O-bis(methoxymethyl)-1,4-dihydroxy-2,3-dimethyl-
5-solanesylbenzene (2b): The above described procedure was per-
formed with 0.22 g (0.24 mmol) [4-13C]-1,4-di-O-bis(methoxyme-
thyl)-6-bromo-1,4-dihydroxy-2,3-dimethyl-5-solanesylbenzene (3b)
in 10 mL ether and 1.0 mL (1.6 mmol) butyllithium to yield 0.21 g
1
3
tained. H NMR (600 MHz): δ ϭ 2.03 [d, J(C-H) ϭ 3.7 Hz, 3 H,
3Ј-CH3], 6.47 [dt, 3J(C-H) ϭ 9.9 Hz and 3J(H-H) ϭ 1.7 Hz, 1 H
ring CH] ppm. 13C NMR (150 MHz): δ ϭ 12.0 [d, 2J(C-C) ϭ
1
3
of crude product. H NMR: δ ϭ 2.14 [d, J(C-H) ϭ 4.1 Hz, 3 H,
3Ј-CH3], 4.88 [d, 2J(C-H) ϭ 3.8 Hz, 1 H, 4-OCH2O], 6.75 [d, 3J(C-
H) ϭ 9.1 Hz, 1 H, 6-CH] ppm. 13C NMR: δ ϭ 148.6 (4-13C) ppm.
3
3.7 Hz, 2Ј-CH3], 118.1 [d, J(C-C) ϭ 2.3 Hz, tail 2-CH], 132.0 [d,
1J(C-C) ϭ 1.7 Hz, 6-CH], 139.6 [d, 4J(C-C) ϭ 1.5 Hz, tail 3-C],
Plastoquinone-9 (1)
1
2
140.5 [d, J(C-C) ϭ 2.0 Hz, 2-C], 140.9 [d, J(C-C) ϭ 51.0 Hz, 3-
C], 147.9 [d, J(C-C) ϭ 49.0 Hz, 5-C], 187.6 (4-13CϭO), 187.8 [d,
2
2,3-Dimethyl5-[(all-E)-3,7,11,15,19,23,27,31,35-nonamethyl-2,6,
3J(C-C) ϭ 8.4 Hz, 1-CϭO] ppm. FT-IR: ν˜ ϭ 2918 (vs), 2850 (s),
10,14,18,22,26,30,34-hexatriacontanonaenyl]-p-benzoquinol: To
a
1661 (m), 1654 (m), 1637 (s), 1608 (vs), 1438 (s), 1381 (s), 1316 (m),
solution of 0.24 g (0.29 mmol) crude 1,4-di-O-bis(methoxymethyl)-
1,4-dihydroxy-2,3-dimethyl-5-solanesylbenzene (2) in 15 mL ace-
tonitrile was added 15 mL H2O. The mixture was cooled in an ice-
bath before 0.50 g (2.99 mmol) 2,6-pyridinedicarboxylic acid and
1.50 g (2.75 mmol) ammonium cerium(VI) nitrate were added. The
mixture was stirred for 15 minutes at 0 °C and for 15 minutes at
room temperature before 20 mL ether was added. The water layer
was separated and extracted twice with ether. The combined or-
ganic layers were washed with saturated NH4Cl, saturated NaCl
and dried over MgSO4. After evaporation of the solvent under va-
cuum, 0.20 g of crude product was obtained. Purification over silica
with 15% ether/85% PE as eluens yielded 0.15 g (0.20 mmol, 71%,
80% from 4) of plastoquinone-9 (1). 1H NMR (600 MHz): δ ϭ
1.58 (s, 3 H, tail cis 35Ј-CH3), 1.60 (s, 21 H, tail 7 CH3), 1.62 (s, 3
H, tail 3Ј-CH3), 1.68 (s, 3 H, tail end trans 36-CH3), 1.98 and 2.06
(m, 32 H, tail 16 CH2), 2.01 (s, 3 H, 2Ј-CH3), 2.03 (s, 3 H, 3Ј-CH3),
3.12 [d, 3J(H-H) ϭ 7.2 Hz, 2 H, tail 1-CH2], 5.16 [t, 3J(H-H) ϭ
7.2 Hz, 1 H, tail 2-CH], 5.09 [t, 3J(H-H) ϭ 6.0 Hz, 1 H, tail 34-
1100 (br. m), 840 (br. m), 418 (m) cmϪ1
.
2,3-Dimethyl-N-(phenylsulfonyl)aniline: To a solution of 6.0 mL
(49.5 mmol) 2,3-dimethylaniline (8) and 4.0 mL (49.5 mmol) pyrid-
ine in 160 mL dichloromethane was added 6.4 mL (49.5 mmol)
benzenesulfonyl chloride. After stirring overnight the mixture was
washed three times with water and dried over MgSO4. After evap-
oration under vacuum the obtained solid was recrystalized in
1
dichloromethane/PE yielding 12.6 g (97%) of a light pink solid. H
NMR: δ ϭ 1.94 (s, 3 H, CH3), 2.20 (s, 3 H, CH3), 6.64 (br. s, 1 H,
3
NH), 7.01 (br. s, 3 H), 7.3Ϫ7.6 (m, 3 H), 7.73 [d, 2 H, J(C-H) ϭ
7.9 Hz] ppm. 13C NMR: δ ϭ 13.7 (CH3), 20.5 (CH3), 123.6 (CH),
125.7 (CH), 127.0 (2 CH), 128.3 (CH), 128.8 (2 CH), 132.0, 132.7
(CH), 133.9, 137.7, 139.5 ppm.
N-(4,4-Dimethoxy-2,3-dimethylcyclohexa-2,5-dien-1-yl)benzene-
sulfonamide (26): A solution of 1.23 g (3.83 mmol) phenyliodonium
diacetate in 16.0 mL methanol was injected over 40 min in a solu-
tion of 0.50 g (1.91 mmol) 2,3-dimethyl-N-(phenylsulfonyl)aniline
in 3.7 mL methanol. The solution turned red-yellow and then be-
came yellow within 40 min. Removal of the methanol under va-
cuum gave a yellow oil which was purified by column chromato-
graphy with dichloromethane yielding 0.57 g (93%) product. 1H
NMR: δ ϭ 1.90 (s, 3 H, CH3), 1.94 (s, 3 H, CH3), 3.17 (s, 6 H, 2
3
3
CH], 5.11 [br. t, J(H-H) ϭ 6.6 Hz, 7 H, tail 7 CH] 6.47 [t, J(H-
H) ϭ 1.7 Hz, 1 H ring CH] ppm. 13C NMR (150 MHz): δ ϭ 12.0
(2Ј-CH3), 12.3 (3Ј-CH3), 16.0 (m, tail 7Ј-, 11Ј-, 15Ј-, 19Ј-, 23Ј-, 27Ј-,
and 31Ј-CH3), 16.1 (tail 3Ј-CH3), 17.6 (tail end cis 35Ј-CH3), 25.7
(tail end trans 36-CH3), 26.5 (tail 32-CH2), 27.4 (tail 1-CH2),
26.6Ϫ26.7 (m, tail 8-, 12-, 16-, 20-, 24-, and 28-CH2), 39.7 (m, tail
5-, 9-, 13-, 17-, 21-, 25-, 29-, and 33-CH2), 118.1 (tail 2-CH), 123.8
(tail 6-CH), 124.1Ϫ124.4 (m, tail 10-, 14-, 18-, 22-, 26-, 30- and 34-
CH), 131.2 (tail 35-C), 132.0 (6-CH), 134.8Ϫ135.0 (tail 11-, 15-,
19-, 23-, 27- and 31-C), 135.4 (tail 7-C), 139.6 (tail 3-C), 140.5 (2-
C), 140.9 (3-C), 147.9 (5-C), 187.6 (4-CϭO), 187.8 (1-CϭO) ppm.
FT-IR: ν˜ ϭ 2965 (m), 2943 (m), 2907 (m), 2847 (m), 1644 (s), 1615
(m), 1446 (m), 1384 (m), 1318 (m), 1107 (m), 892 (m), 874 (s), 796
3
CH3O), 6.72 [d, 1 H, J(C-H) ϭ 9.4 Hz, 5-H], 7.5Ϫ7.7 (m, 3 H),
7.76 [d, 1 H, 3J(C-H) ϭ 9.4 Hz, 6-H], 8.02 [d, 2 H, 3J(C-H) ϭ
7.6 Hz] ppm. 13C NMR: δ ϭ 12.3 (3Ј-CH3), 13.7 (2Ј-CH3), 50.8 (2
CH3O), 94.7 (4-C), 125.8 (CH), 126.6 (2 CH), 128.6 (2 CH), 132.5
(6-CH), 134.2 (2-C), 141.3 (CS), 143.3 (5-CH), 150.2 (3-C), 163.8
(CϭN) ppm.
(s), 602 (m), 476 (s), 456 (m), 412 (s) cmϪ1
.
[1-13C]-Plastoquinone-9 (1a): The above described procedure was
performed with 0.21 g (0.25 mmol) [1-13C]-1,4-di-O-bis(methoxy-
4,4-Dimethoxy-2,3-dimethyl-p-benzoquinone Mono Ketal (27): To a
methyl)-1,4-dihydroxy-2,3-dimethyl-5-solanesylbenzene (2a) in 15 solution of 2.10 g (6.535 mmol) N-(4,4-dimethoxy-2,3-dimethylcy-
mL acetonitrile, 15 mL water, 0.50 g (2.99 mmol) 2,6-pyridinedicar- clohexa-2,5-dien-1-yl)benzenesulfonamide (26) in 110 mL ether
boxylic acid and 1.50 g (2.75 mmol) ammonium cerium(VI) nitrate and 110 mL 1.0 KOH solution were added 2.11 g (6.535 mmol)
to yield 0.17 g of crude product. After purification over silica 0.10 g tetrabutylammonium bromide and 1.34 g (7.842 mmol) phenyl
(53%, 69% from 4a) pure [1-13C]-plastoquinone-9 (1a) was ob- bromide. After overnight stirring the phases were separated and the
1
3
tained. H NMR (600 MHz: δ ϭ 2.01 [d, J(C-H) ϭ 3.7 Hz, 3 H,
aqueous layer was extracted twice with ether. The combined or-
2Ј-CH3] ppm. 13C NMR (150 MHz): δ ϭ 12.0 [d, 2J(C-C) ϭ ganic layers were dried over MgSO4. After evaporation under va-
1.5 Hz, 2Ј-CH3], 12.3 [d, 3J(C-C) ϭ 3.8 Hz, 3Ј-CH3], 27.4 [d, 3J(C-
cuum the crude residue was purified by column chromatography
C) ϭ 4.4 Hz, tail 1-CH2], 132.0 [d, 1J(C-C) ϭ 53.3 Hz, 6-CH], 140.5 with diethyl ether/PE (40:60) yielding 1.03 g (86%) of a light-yellow
[d, 1J(C-C) ϭ 50.1 Hz, 2-C], 140.9 [d, 2J(C-C) ϭ 2.0 Hz, 3-C], 147.9 oil. 1H NMR: δ ϭ 1.91 (s, 6 H, 2 CH3), 3.19 (s, 6 H, 2 CH3O),
[d, 2J(C-C) ϭ 1.5 Hz, 5-C], 187.6 [d, 3J(C-C) ϭ 8.4 Hz, 4-CϭO],
6.43 [d, 1 H, 3J(C-H) ϭ 10.1 Hz, 5-H], 6.73 [d, 1 H, 3J(C-H) ϭ
187.8 (1-13CϭO) ppm. FT-IR: ν˜ ϭ 2919 (m), 2852 (m), 1646 (s), 10.1 Hz, 6-H] ppm. 13C NMR: δ ϭ 10.8 (3Ј-CH3), 13.1 (2Ј-CH3),
1617 (m), 1604 (s), 1448 (s), 1381 (s), 1099 (br. m), 840 (br. m), 418
50.8 (2 CH3O), 95.7 (4-C), 132.1 (6-CH), 135.2 (2-C), 143.2 (5-
CH), 149.2 (3-C), 184.6 (CO) ppm.
(m), 412 (m) cmϪ1
.
Eur. J. Org. Chem. 2002, 2094Ϫ2108
2107