C. Naphthalene Derivatives
95
and Gauhe (1943) confirmed structure 11 for echinochrome by a one-step
Friedel-Crafts synthesis from 2-ethyl-l,3,4-trimethoxybenzene (12) and
dibenzoyloxymaleic anhydride (13) in an aluminum chloride-sodium chloride
melt in a yield of 1.5-2%, after acidification and purification via a column of
calcium carbonate.
OH
Ο
OMe
0
ΗΟ
ών (éf ~A
OH
Ο
OMe
Ο
11
12
13
Lederer (1938) in the course of an extensive investigation of carotenoid
pigments of invertebrates noted that a crystalline pigment extracted from the
spines of Strongylocentrotus
(Paracentrotus) lividus was not a carotenoid.
Lederer and Glaser (1938) described the isolation of this pigment, which
they named spinochrome, and characterized it—mp 185°, composition
C 1 2 H 1 0 O 8 . Accordingly, they believed it to be a hydroxyechinochrome.
Kuhn and Wallenfels (1941) isolated from the spines and tests (shells) of the
sea urchin Arbacia pustulosa a pigment, mp 229°-230°, of composition
C 1 2 H 8 0 8 , which they named spinone A. In two crucial experiments, Kuhn
and Wallenfels (1941) carried out a chromic acid oxidation that furnished
acetic rather than propionic acid, and performed a reductive acetylation to a
leucooctaacetate. On the basis of these results, and in analogy with the
echinochrome structure (11), these workers proposed structure 14 for spinone
A. Kuhn and Wallenfels (1941) expressed the view that their spinone A (14),
C 1 2 H 8 H 8 , might be an artifact, and that the true spine pigment might be
Lederer and Glaser's (1938) spinochrome, Ci 2 H 1 0 O 8 , which became oxidized
during work-up, and whose structure would differ from that of spinone A by
an alcoholic rather than ketonic side chain.
OH
Ο
HO
rxT
HO^Y^Y^COCHa
OH
Ο
14
The distinction between echinochromes, i.e., pigments isolated from the
eggs, ovaries, body fluids, etc., of echinoids (sea urchins) on one hand, and
spinochromes, i.e., pigments isolated from the calcareous spines and shells
of echinoids, is no longer justified. Echinochrome (11), which subsequently
95
and Gauhe (1943) confirmed structure 11 for echinochrome by a one-step
Friedel-Crafts synthesis from 2-ethyl-l,3,4-trimethoxybenzene (12) and
dibenzoyloxymaleic anhydride (13) in an aluminum chloride-sodium chloride
melt in a yield of 1.5-2%, after acidification and purification via a column of
calcium carbonate.
OH
Ο
OMe
0
ΗΟ
ών (éf ~A
OH
Ο
OMe
Ο
11
12
13
Lederer (1938) in the course of an extensive investigation of carotenoid
pigments of invertebrates noted that a crystalline pigment extracted from the
spines of Strongylocentrotus
(Paracentrotus) lividus was not a carotenoid.
Lederer and Glaser (1938) described the isolation of this pigment, which
they named spinochrome, and characterized it—mp 185°, composition
C 1 2 H 1 0 O 8 . Accordingly, they believed it to be a hydroxyechinochrome.
Kuhn and Wallenfels (1941) isolated from the spines and tests (shells) of the
sea urchin Arbacia pustulosa a pigment, mp 229°-230°, of composition
C 1 2 H 8 0 8 , which they named spinone A. In two crucial experiments, Kuhn
and Wallenfels (1941) carried out a chromic acid oxidation that furnished
acetic rather than propionic acid, and performed a reductive acetylation to a
leucooctaacetate. On the basis of these results, and in analogy with the
echinochrome structure (11), these workers proposed structure 14 for spinone
A. Kuhn and Wallenfels (1941) expressed the view that their spinone A (14),
C 1 2 H 8 H 8 , might be an artifact, and that the true spine pigment might be
Lederer and Glaser's (1938) spinochrome, Ci 2 H 1 0 O 8 , which became oxidized
during work-up, and whose structure would differ from that of spinone A by
an alcoholic rather than ketonic side chain.
OH
Ο
HO
rxT
HO^Y^Y^COCHa
OH
Ο
14
The distinction between echinochromes, i.e., pigments isolated from the
eggs, ovaries, body fluids, etc., of echinoids (sea urchins) on one hand, and
spinochromes, i.e., pigments isolated from the calcareous spines and shells
of echinoids, is no longer justified. Echinochrome (11), which subsequently