Sökning: id:"swepub:oai:DiVA.org:kth-6646" >
Enantiopure buildin...
-
Larsson, MichaelMittuniversitetet,Institutionen för naturvetenskap (-2008)
(författare)
Enantiopure building blocks for the synthesis of 3-methyl-2-alkanols. Diastereoselective methylmetal addition to a chiral 2-methylaldehyde followed by lipase catalysed esterification
- Artikel/kapitelEngelska2004
Förlag, utgivningsår, omfång ...
-
Elsevier BV,2004
-
printrdacarrier
Nummerbeteckningar
-
LIBRIS-ID:oai:DiVA.org:kth-6646
-
https://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-6646URI
-
https://doi.org/10.1016/j.tetasy.2004.07.049DOI
-
https://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-873URI
Kompletterande språkuppgifter
-
Språk:engelska
-
Sammanfattning på:engelska
Ingår i deldatabas
Klassifikation
-
Ämneskategori:ref swepub-contenttype
-
Ämneskategori:art swepub-publicationtype
Anmärkningar
-
QC 20101020
-
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 och genrebeteckningar
Biuppslag (personer, institutioner, konferenser, titlar ...)
-
Andersson, JimmyMittuniversitetet,Institutionen för naturvetenskap (-2008)(Swepub:miun)jimand
(författare)
-
Liu, RongMittuniversitetet,Institutionen för naturvetenskap (-2008)(Swepub:miun)exronliu
(författare)
-
Högberg, Hans-ErikMittuniversitetet,Institutionen för naturvetenskap (-2008)(Swepub:miun)hansho
(författare)
-
MittuniversitetetInstitutionen för naturvetenskap (-2008)
(creator_code:org_t)
Sammanhörande titlar
-
Ingår i:Tetrahedron: Elsevier BV15, s. 2907-29150957-41661362-511X
Internetlänk
Hitta via bibliotek
Till lärosätets databas