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Enantiopure buildin...
Enantiopure building blocks for the synthesis of 3-methyl-2-alkanols. Diastereoselective methylmetal addition to a chiral 2-methylaldehyde followed by lipase catalysed esterification
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- Larsson, Michael (författare)
- Mittuniversitetet,Institutionen för naturvetenskap (-2008)
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- Andersson, Jimmy (författare)
- Mittuniversitetet,Institutionen för naturvetenskap (-2008)
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- Liu, Rong (författare)
- Mittuniversitetet,Institutionen för naturvetenskap (-2008)
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- Högberg, Hans-Erik (författare)
- Mittuniversitetet,Institutionen för naturvetenskap (-2008)
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(creator_code:org_t)
- Elsevier BV, 2004
- 2004
- Engelska.
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Ingår i: Tetrahedron. - : Elsevier BV. - 0957-4166 .- 1362-511X. ; 15, s. 2907-2915
- Relaterad länk:
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http://www.sciencedi...
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https://urn.kb.se/re...
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https://doi.org/10.1...
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https://urn.kb.se/re...
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Abstract
Ämnesord
Stäng
- The racemic synthetic building block (2R*,3R*)-3-methyl-4-(phenylsulfanyl)butan-2-ol (2R*,3R*)-2 was obtained in a high diastereomeric ratio [95:5, (2R*,3R*)/(2R*,3S*)-ratio] by Lewis acid catalysed dimethylzinc addition to racemic 2-methyl-3-(phenylsulfanyl)propanal (rac-1). Two consecutive acylations with vinyl acetate catalysed by Chirazyme L-2 (immobilised Candida antarctica lipase 13, CAL-B) led to preferential esterification of three of the four stereoisomers leaving (2S,3S)-3-methyl-4-(phenylsulfanyl)butan-2-ol (2S,3S)-2 of 98:2 dr and 98% ee. The stereoisomerically impure acetate of (2R,3R)-3-methyl-4-(phenyisulfanyl)butan-2-ol (2R,3R)-2, obtained in the first CAL-B-catalysed acylation step, was hydrolysed and reesterified using CAL-A (immobilised Novozyme SP 525) as the catalyst, which left (2R,3R)-3-methyl-4-(phenylsulfanyl)butan-2-ol (2R,3R)-2 of 98:2 dr and 99% ee as the remaining substrate. The individual enantiomers of 2-methyl-3-(phenylsulfanyl)propanal 1 were prepared from readily available (S)- and (R)-3-hydroxy-2-methylpropanoic acid methyl ester and reacted with dimethylzinc to give both enantiomers of (2R*,3R*)-3-methyl-4-(phenylsulfanyl)butan-2-ol (2R, 3R)- or (2S,3S)-2 of both high dr and ee. These products were purified by lipase catalysed acylation to give the enantiomerically and diastereomerically highly pure enantiomers (>99.5:0.5 dr, >99.9% ee). Pure (2S,3S)-3-methyl-4-(phenylsulfanyl)butan-2-ol (2S,3S)-2 was transformed into a potential pheromone precursor isolated from some pine sawflies of the genus Gilpinia, (2S,3R)-3-methylpentadecan-2-ol in 54% yield over eight steps.
Ämnesord
- NATURVETENSKAP -- Kemi (hsv//swe)
- NATURAL SCIENCES -- Chemical Sciences (hsv//eng)
- TEKNIK OCH TEKNOLOGIER -- Industriell bioteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Industrial Biotechnology (hsv//eng)
Nyckelord
- hypophosphite combination system
- enantioselective total synthesis
- candida-antarctica lipase
- sex-pheromone
- secondary alcohols
- raney-nickel
- reductive desulfurization
- macrodiprion-nemoralis
- microdiprion-pallipes
- neodiprion-sertifer
- Chemistry
- Kemi
- Bioengineering
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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