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Reaction with NaN3 (only with 1)
GC-MS estimation: allomaltol (11; C6H6O3; traces; retention time: 6.5 min) was manifested by
peaks at m/z 126 (100%), 98 (15%, ±CO), 85 (5%, ±CH), 69 (45%, ±CHO) in the GC-MS.
Azidokojic acid (C6N5N3O3): yield: 40% white-beige crystals; m.p.: 18±120ꢀC (Ref [6, 7]: m.p.:
120ꢀC); IR (KBr): ꢀ 3239 (ꢀOH), 2118 (ꢀN3), 1665 (ꢀCO) cm 1; MS: m/z 167 (80%), 139 (70%,±
N2), 125 (20%, ±N), 110 (±CH2), 97, 69, 54 (identical with that of an authentic sample).
Reaction with NaSCN (only with chlorokojic acid)
GC-MS estimation: 11 (retention time: 6.5 min, m/z 126, fragmentation identical as above)
chlorokojic acid (1; C6H5ClO3; retention time: 8.32 min, m/z 160 (100%), 125 (80%, ±Cl), 97
(40%), 69 (50%), 39 (70%), 29 (45%)), thiolokojic acid (14; C6H6SO3; retention time: 9.17 min,
m/z 158 (100%), 125 (30%, ±SH), 97, 69, 41), thiocyanatokojic acid (13; C7H5NO3S; retention
time: 10.82 min, m/z 183 (100%), 158 (10%, ±CN), 125 (30%, ±S), 97, 67, 39), isothiocyana-
tokojic acid (retention time: 11.08, m/z 183 (30%), 125 (100%, ±NCS), 97, 67, 39).
Allomaltol (11) was isolated by preparative TLC. Colourless prisms; m.p.: 145±149ꢀC (Ref. [8]:
m.p.: 149±150ꢀC, Ref. [18]: 152±153ꢀC); GC-MS: identical to those given above; IR (KBr):
ꢀ 3215 (ꢀOH), 2926 (ꢀCH ), 1652 (ꢀCO), 1615 (ꢀCOÁ Á ÁHO), 1231 (ꢁCOC) cm 1; 1H NMR (DMSO-d6,
3
ꢁ): 9.00 (s, 1H, HOH), 7.99 (s, 1H, H6), 6.25 (s, 1H, H3), 2.24 (t, 3H, HCH ) ppm.
The residual crude mixture of thiocyanato-, isothiocyanato-, and thiolo-kojic acids could not be
separated.
3
Reaction of 1 with Nal
GC-MS analysis: iodoacetone (C3H5IO; (retention time: 4.80 min, m/z 184 (80%), 169 (10%, ±
CH3), 141 (30%, ±CO), 127 (30%, ±I), 43 (100%, C2H3O)), 11 (retention time : 7.8 min, m/z 126,
fragmentation identical to that given above), iodokojic acid (10; C6H5IO3; retention time: 11.0 min,
m/z 252 (15%), 125 (100%, ±I), 97, 67, 39). The ®ltrate gradually decomposed with liberation of
elemental iodine (blue staining of starch paper strips) when stored on air and exposed to sunlight.
Isolated on preparative TLC plates: iodokojic acid (10); yellow lea¯ets (78%), m.p.: 175±178ꢀC
(Ref. [8]: m.p.: 176±177ꢀC, Ref. [2]: m.p. 180±181ꢀC); sublime at about 130ꢀC; MS: m/z and
fragmentation identical to those given above; IR (KBr): ꢀ 3241 (ꢀOH), 1653 (ꢀCO), 1615
(ꢀCOÁ Á ÁOH), 501 (ꢀCI) cm 1; 1H NMR (DMSO-d6, ꢁ): 9.24 (s, 1H, OH), 8.05 (s, 1H, H6), 6.57 (s, 1H,
H3) 4.39 (d, 2H, CH2) ppm; in addition 11 (up to 30%) with MS, IR, and 1H NMR spectra identical
to those reported above.
Reaction of methyl chlorokojate with Nal
GC-MS analysis: 5-O-Methyl allomaltol (11, R OMe;C7H7IO3; retention time: 5.7 min, m/z 140
(80%), 111 (30%, ±CH3), 95 (100%, ±CH2O), 69 (30%); the fragmentation is in agreement with that
reported in Ref. [19]), 2-formyl-5-methoxypyran-4-one (retention time: 6.7 min, m/z 154 (60%),
126 (40%, ±CHO), 95 (100%)), methyl chlorokojate (15, R OMe; C7H7ClO3; unreacted, retention
time: 7.25 min, m/z 174 (25%), 139 (50%, ±Cl), 111 (25%, ±CO), 95 (100%, C5H3O2)),
iodoacetone (retention time: 7.54, m/z 184, fragmentation as above), methyl kojate (12, R OMe;
C7H8O4; retention time: 8.26 min, m/z 156 (50%), 138 (15%, ±O), 125 (30%, ±CH), 95 (100%)),
methyl iodokojate (10, R OMe; C7H7IO3; retention time: 8.7 min, m/z 266 (25%), 139 (100%,
±I), 111 (80%, ±CO), 95 (50%)).
Isolated on preparative TLC plate: methyl iodokojate; yellow crystals, m.p.: 118±122ꢀC; MS: m/
z 266 with fragmentation identical to that given above; IR (KBr): ꢀ 1646 (ꢀCO), 1421 (ꢀOCH ),
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1
524 (ꢀCl) cm
.