Helvetica Chimica Acta ± Vol. 81 (1998)
1689
[(7Z,10Z,13Z)-hexadeca-7,10,13-trienoyl]-sn-glycerol (6, tR 5.9 min; 1.9 mg, 70%). MeOH eluates from column
washing after each HPLC cycle were combined and evaporated and the residue was subjected to reversed-phase
HPLC (MeOH/H2O 95 :5) to give (9Z,12Z,15Z)-octadeca-9,12,15-trienoic acid ( linolenic acid; 4; tR 8.5 min;
1.0 mg).
On the same treatment, 3 (3.2 mg) gave 3-O-b-d-galactopyranosyl-1-O-[(9Z,12Z,15Z)-octadeca-9,12,15-
trienoyl]-sn-glycerol (7; tR 6.8 min; 1.3 mg) and 4 (0.8 mg).
Data of 4: 1H-NMR (CD3OD): 2.33 (t, J 7.0, 2 H C(2)); 1.63 (m, 2 H C(3)); 1.37 (m, 2 H C(4) to
2 H C(7)); 2.09 (m, 2 H C(8), 2 H C(17)); 5.36 (m, H C(9), H C(10), H C(12), H C(13), H C(15),
H
C(16)); 2.81 (m, 2 H C(11), 2 H C(14)); 0.98 (q, J 7.5, Me).
Data of 6: 1H-NMR (CD3OD): 4.15 (m, 2 H C(1)); 3.99 (m, H C(2)); 3.94, 3.68 (2m, 2 H C(3)); 2.31
(t, J 7.3, 2 H C(2')); 1.63 (m, 2 H C(3')); 1.38 (m, 2 H C(4'), 2 H C(5')); 2.08 (m, 2 H C(6'), 2 H C(15'));
5.35 (m, H C(7'), C(8'), C(10'), C(11'), C(13'),
H
H
H
H
H
C(14')); 2.81 (t, J 5.7, 2 H C(9'),
2 H C(12')); 0.98 (q, J 7.5, Me); 4.23 (d, J 7.4, H C(1'')); 3.51 (m, H C(2''), H C(5'')); 3.46 (dd, J 9.6,
3.3, H C(3'')); 3.81 (dd, J 3.3, 1.0, H C(4'')); 3.74 (m, 2 H C(6'')). 13C-NMR (CD3OD): 175.36 (s); 132.70
(d); 130.84 (d); 129.20 (d); 129.13 (d); 128.98 (d); 128.18 (d); 105.29 (d); 76.74 (d); 74.81 (d); 72.53 (d); 71.85
(d); 70.24 (d); 69.59 (t); 66.55 (t); 62.44 (t); 34.87 (t); 30.37 (t); 29.79 (t); 27.99 (t); 26.48 (t); 26.37 (t); 25.84 (t);
21.40 (t); 14.62 (q). FAB-MS (glycerol): 509 ([M Na] ).
Data of 7: 1H-NMR (CD3OD): 4.15 (m, 2 H C(1)); 3.99 (m, H C(2)); 3.94, 3.67 (2m, 2 H C(3)); 2.33
(t, J 7.0, 2 H C(2')); 1.63 (m, 2 H C(3')); 1.37 (m, 2 H C(4') to 2 H C(7')); 2.09 (m, 2 H C(8'),
2 H C(17')); 5.36 (m, H C(9'),
H
C(10'),
H
C(12'),
H
C(13'),
H
C(15'),
H C(16')); 2.82
(m, 2 H C(11'), 2 H C(14')); 0.98 (q, J 7.5, Me); 4.22 (d, J 7.4, H C(1'')); 3.51 (m, H C(2''), H C(5''));
3.46 (dd, J 9.6, 3.3, H C(3'')); 3.82 (dd, J 3.3, 1.0, H C(4'')); 3.74 (m, 2 H C(6'')). FAB-MS (glycerol): 537
([M Na] ).
Alkaline Hydrolysis of Compounds 1 ± 3. Compound 2 (3.3 mg), on storage in CD3OD (0.6 ml) for 45 days
at 48 and then 24 h at 508, was partially converted into compounds 6 (see Scheme 2, a, and Footnote 2) and
(D3)methyl (9Z,12Z,15Z)-octadeca-9,12,15-trienoate (8); NMR observation was carried out on products 6 and 8
after aqueous workup. On addition of catal., solid NaHCO3, the hydrolysis went to completion, giving 1-O-b-d-
galactopyranosyl-sn-glycerol (9) and (D3)methyl (7Z,10Z,13Z)-hexadeca-7,10,13-trienoate (10). The mixture
was subjected to reversed-phase HPLC (MeOH/H2O 95 :5): 9 (tR 2.5 min; 1.1 mg, 93%), 8 (tR 9.8 min; 1.2 mg),
and 10 (tR 6.9 min; 1.1 mg).
Under similar conditions, 8 ´ 10 3 m 3 in CD3OD was partially converted into 7 and 8 (see Footnote 2).
In another experiment, sat. methanolic Na2CO3 soln. (1 ml) was added to 1 ± 3 (3 :1:2; 10.0 mg), stirring the
mixture at r.t. until complete conversion (1 h, TLC). The residue from evaporation was subjected to reversed-
phase HPLC (MeOH/H2O 95 :5): 9 (tR 2.5 min; 3.2 mg, 90%), methyl (7Z,10Z,13Z)-hexadeca-7,10,13-trienoate
(11; tR 6.2 min; 3.0 mg), and methyl (9Z,12 Z,15Z)-octadeca-9,12,15-trienoate (12; tR 8.9 min; 3.3 mg).
Data of 8: 1H-NMR (CD3OD): 2.33 (t, J 7.0, 2 H C(2)); 1.63 (m, 2 H C(3)); 1.37 (m, 2 H C(4) to
2 H C(7)); 2.09 (m, 2 H C(8), 2 H C(17)); 5.36 (m, H C(9), H C(10), H C(12), H C(13), H C(15),
.
H
C(16)); 2.82 (m, 2 H C(11), 2 H C(14)); 0.97 (q, J 7.5, Me). EI-MS: 295 (14, M ), 266(3), 252(1),
149(21), 109(119), 79(100).
Data of 9: semisolid. [aD25
6.8 (c 0.2, H2O) ([7c]: [a]D
7.0 (c 0.3, H2O); [15a]: [a]D
8.0 (c
0.6, H2O)). 1H-NMR: data matched those in [15a]. 13C-NMR (CD3OD): 105.14 (d); 76.70 (d); 74.78 (d); 72.54
(d); 72.09 (d); 72.01 (t); 70.36 (d); 64.01 (t); 62.51 (t). FAB-MS (glycerol): 277 ([M Na] ).
1
Data of 10: H-NMR (CD3OD): 5.37 (m, H C(7), H C(8), H C(10), H C(11), H C(13), H C(14));
2.31 (t, 2 H C(2)); 1.64 (m, 2 H C(3)); 1.39 (m, 2 H C(4), 2 H C(5)); 2.08 (m, 2 H C(6), 2 H C(15)); 2.82
(m, 2 H C(9), 2 H C(12)); 0.97 (q, J 7.5, 3 H C(16)). 13C-NMR (CD3OD): 174.60 (s); 132.73 (d); 130.86
(d); 129.22 (d); 129.16 (d); 129.04 (d); 127.31 (d); 50.41 (q); 34.78 (t); 30.68 (t); 30.36 (t); 29.79 (t); 27.99 (t);
.
26.51 (t); 25.92 (t); 20.90 (t); 14.64 (q). EI-MS: 267 (14, M ), 238(2), 224(2), 149(10), 109(12), 79(100).
.
Data of 11: 1H-NMR: data in agreement with [8]. EI-MS: 264 (13, M ), 235(1), 233(2), 149(8), 121(26),
109(18), 107(19), 109(18), 79(100).
Data of 12: 1H-NMR (CD3OD): 2.33 (t, J 7.0, 2 H C(2)); 1.63 (m, 2 H C(3)); 1.37 (m, 2 H C(4) to
2 H C(7)); 2.09 (m, 2 H C(8), 2 H C(17); 5.36 (m, H C(9), H C(10), H C(12), H C(13), H C(15),
H
M
C(16)); 2.82 (m, 2 H C(11), 2 H C(14)); 0.98 (q, J 7.5, 3H C(18)); 3.65 (s, MeO). EI-MS: 292 (13,
.
), 263(3), 261(5), 149(15), 135(18), 121(26), 109(18), 69(20).
(Z)-2-Hydroxy-3-(4-hydroxyphenyl)prop-2-enoic Acid Methyl Ester (13a). 1H-NMR (CD3OD): 7.81
(d, J(2',3') J(6',5') 8.7,
H
C(2'),
H
C(6')); 6.76 (d, J(3',2') J(6',5') 8.7,
H C(3'), H C(5')); 7.05
(s, H C(3)); 3.82 (s, MeO). 13C-NMR (CD3OD): 137.08 (s, C(1')); 134.10 (d, C(2'), C(6')); 116.22 (d, C(3'),