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A facile approach t...
A facile approach to diosgenin and furostan type saponins bearing a 3 beta-chacotriose moiety
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- Lahmann, Martina, Docent i kemi, 1963- (författare)
- Department of Organic Chemistry, Stockholm University, S-10691 Stockholm, Sweden
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Gyback, H (författare)
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Garegg, P J (författare)
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Oscarson, S (författare)
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Suhr, R (författare)
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Thiem, J (författare)
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(creator_code:org_t)
- Elsevier BV, 2002
- 2002
- Engelska.
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Ingår i: Carbohydrate Research. - : Elsevier BV. - 0008-6215 .- 1873-426X. ; 337:21-23, s. 2153-2159
- Relaterad länk:
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Ämnesord
Stäng
- Combination of a one-pot coupling technique and the use of benzyl ethers as permanent protecting groups offered a short and simple route to dioscin-type saponins. This strategy in combination with a mild reductive opening procedure of the spiroketal function in diosgenin also offered a convenient approach to bidesmosidic furostan type saponins. (Me3NBH3)-B-./AlCl3 promoted acetal opening of 3-O-TBDMS-protected diosgenin gave the 26-OH acceptor 9 into which a benzylated beta-glucose moiety was introduced by a S(N)2-type imidate coupling. After cleavage of the silyl ether, the 3beta-O-glucose and the 4-O-linked rhamnose of the chacotriose unit were introduced by a NIS/AgOTf-promoted one-pot coupling sequence utilising thioglycoside donors and their different reactivity in different solvents. After removal of a benzoyl group, the same coupling conditions were also used for the coupling of the second 2-O-linked rhamnose unit. The target substance was obtained after cleavage of the protecting benzyl ethers under Birch-type conditions, which did not affect the double bond in the steroid skeleton.
Ämnesord
- NATURVETENSKAP -- Kemi -- Organisk kemi (hsv//swe)
- NATURAL SCIENCES -- Chemical Sciences -- Organic Chemistry (hsv//eng)
Nyckelord
- saponins
- one-pot glycosylation
- reductive acetal opening
- birch-type reduction
- chacotriose
- diosgenin
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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