Use of 1,2-dichloro 4,5-dicyanoquinone (DDQ) for cleavage of the 2-naphthylmethyl (NAP) group

Xia, Jie; Abbas, Saeed A.; Locke, Robert D.; Piskorz, Conrad F.; Alderfer, James L.; Matta, Khushi L.

doi:10.1016/s0040-4039(99)02046-8

Cited by 176 publications

(114 citation statements)

References 21 publications

Supporting

Mentioning

108

Contrasting

Order By: Relevance

“…Com-pound 6 was converted to the glycosyl acceptor 2 by a series of reactions involving deacetylation, protection of primary alcohol with tert-butyldiphenylsilyl (TBDPS) chloride and benzoylation (7) (57%, 3 steps), followed by removal of the TBDPS group (94%). Acceptor 3 was prepared from known 2-(trimethylsilyl) ethyl 3-O-(2-naphthylmethyl)-β-Dgalactopyranoside (8) 24) by the following five-step procedure. Protection of primary alcohol with tert-butyldimethylsilyl (TBDMS) chloride, followed by benzoylation gave compound 9 (79%, 2 steps).…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Antigenicity against Human Sera of a Biotin-Labeled Oligosaccharide Portion of a Glycosphingolipid from the Parasite <i>Echinococcus multilocularis</i>

Hada

Kitamura

Yamano

et al. 2016

CHEMICAL & PHARMACEUTICAL BULLETIN

View full text Add to dashboard Cite

Synthesis of a biotinylated analog of the carbohydrate portion of a glycosphingolipid from the parasite Key words glycosphingolipid; Echinococcus multilocularis; biotin probe; chemical synthesisIn our continuing studies to elucidate the biological function of carbohydrate moieties of glycosphingolipids (GSLs) and glycoproteins (GPs) from invertebrates, we have synthesized oligosaccharides found in various Protostomia phyla.

show abstract

Section: Resultsmentioning

confidence: 99%

Synthesis and Antigenicity against Human Sera of a Biotin-Labeled Oligosaccharide Portion of a Glycosphingolipid from the Parasite <i>Echinococcus multilocularis</i>

Hada

Kitamura

Yamano

et al. 2016

CHEMICAL & PHARMACEUTICAL BULLETIN

View full text Add to dashboard Cite

show abstract

“…Since removal of the benzyl groups was not satisfactory for the practical synthesis of 1, the NAP group was chosen as an alternative protective group that can be chemoselectively removed under oxidative conditions and can survive the variety of conditions used in the total synthesis (50,51). In fact, the stability of NAP ethers up to 26 was proven in several reactions, as shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

First- and second-generation total synthesis of ciguatoxin CTX3C

Inoue

Miyazaki

Uehara

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

115

View full text Add to dashboard Cite

More than 20,000 people suffer annually from ciguatera seafood poisoning in subtropical and tropical regions. The extremely low content of the causative neurotoxins, designated as ciguatoxins, in fish has hampered isolation, detailed biological studies, and preparation of anti-ciguatoxin antibodies for detecting these toxins. Furthermore, the large (3 nm in length) and complex molecular structure of ciguatoxins has impeded chemists from completing their total synthesis. In this article, the full details of studies leading to the total synthesis of ciguatoxin CTX3C are provided. The key elements of the first-generation approach include O,O-acetal formation from the right and left wing fragments, conversion from O,O-acetal to O,S-acetal, a radical reaction to cyclize the G ring, a ring-closing metathesis reaction to close the F ring, and final removal of the 2-naphtylmethyl protective groups. Subsequent studies provided a second-generation total synthesis, which is more concise and results in a higher yield. Second-generation synthesis was accomplished by using a direct method of constructing the key intermediate O,S-acetal from ␣-chlorosulfide and a secondary alcohol. These syntheses ensure a practical supply of ciguatoxin for biological applications.ciguatera ͉ polyether ͉ convergent strategy C iguatera is a human intoxication caused by the ingestion of certain reef fish (1). More than 20,000 people suffer annually from ciguatera, making it one of the most common forms of nonbacterial food poisoning. Ingestion of affected fish leads to neurological, gastrointestinal, and cardiovascular disorders, which may last up to a month or more. The most prominent symptom is a disorder of temperature sensation. Specifically, touching cold water can induce pain similar to that of an electric shock. Other symptoms include diarrhea, vomiting, muscle pain and itching, whereas paralysis, coma, and even death may occur in severe cases.Yasumoto et al. (2) identified an epiphytic dinoflagellate, Gambierdiscus toxicus, as the causative organism and demonstrated that dinoflagellate-derived toxins are transferred by the food chain to various fish. About 100 species of fish cause ciguatera, and ciguateric fish look, taste, and smell like normal uncontaminated fish. In addition, the occurrence of poisoning is completely unpredictable. Current difficulties in predicting, detecting, and treating ciguatera have had an adverse socioeconomic impact, in particular, in developing countries.Ciguatoxins are regarded as the principal causative toxins of ciguatera seafood poisoning (Fig. 1) (3, 4). In 1989, the Yasumoto group successfully elucidated the structures of ciguatoxin (CTX) (4) and CTX4B (3) (5, 6), which were found to be large polycyclic ethers having molecular lengths Ͼ3 nm. They subsequently isolated other congeners including CTX3C (1) (7) and 51-hydroxyCTX3C (2) (8). To date, the structures of Ͼ20 congeners of ciguatoxins have been determined (9, 10).The lethal potencies of ciguatoxins (LD 50 ϭ 0.25-4 g͞kg) by i.p. injection into mic...

show abstract

“…However, the PMB group has the disadvantage of extreme acid-sensitivity. The 2-(naphthyl)methyl (NAP) group, 5,6 being removable by either catalytic hydrogenation [6][7][8] or DDQ 9 in the presence of benzyl ether and, unlike its p-methoxybenzyl counterpart, being stable under acidic conditions, seems to be a remarkably useful protecting group for polyhydroxy systems.…”

Section: Introductionmentioning

confidence: 99%

Selective removal of the (2-naphthyl)methyl protecting group in the presence of p-methoxybenzyl group by catalytic hydrogenation

Lázár¹,

Jánossy²,

Csávás³

et al. 2012

Arkivoc

View full text Add to dashboard Cite

show abstract

Use of 1,2-dichloro 4,5-dicyanoquinone (DDQ) for cleavage of the 2-naphthylmethyl (NAP) group

Cited by 176 publications

References 21 publications

Synthesis and Antigenicity against Human Sera of a Biotin-Labeled Oligosaccharide Portion of a Glycosphingolipid from the Parasite <i>Echinococcus multilocularis</i>

Synthesis and Antigenicity against Human Sera of a Biotin-Labeled Oligosaccharide Portion of a Glycosphingolipid from the Parasite <i>Echinococcus multilocularis</i>

First- and second-generation total synthesis of ciguatoxin CTX3C

Selective removal of the (2-naphthyl)methyl protecting group in the presence of p-methoxybenzyl group by catalytic hydrogenation

Contact Info

Product

Resources

About