Linked Life Data

19688787

Source:http://linkedlifedata.com/resource/pubmed/id/19688787

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2009-10-6
pubmed:abstractText
Diastereocontrolled Lewis acid-catalyzed preparation of enantiopure carbacepham derivatives have been developed starting from 2-azetidinone-tethered enals. The BF3.Et2O-promoted reaction of alkenylaldehydes 1 and 16 is effective as carbocyclization protocol to afford 4-substituted 5-hydroxycarbacephams or 3-substituted 4,5-dihydroxycarbacephams, respectively, by a type I carbonyl-ene reaction, while the BF3.Et2O or SnCl4-mediated type II carbonyl-ene cyclization of alkenylaldehydes 2 furnishes 3-methylene 5-hydroxycarbacephams along with the corresponding 3-halo 5-hydroxycarbacepham. The stereochemical outcome of these carbonyl-ene cyclizations leading to carbacepham derivatives can be explained in terms of six-membered, cyclic chair-like transition-state models. The formation of halocarbacepham derivatives is proposed to proceed by a stepwise mechanism.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1861-471X
pubmed:author
pubmed:issnType
Electronic
pubmed:day
5
pubmed:volume
4
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1604-11
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Lewis acid-assisted ene cyclization of 2-azetidinone-tethered enals: synthesis of enantiopure carbacepham derivatives.
pubmed:affiliation
Departamento de Química Orgánica I, Facultad de Química, Universidad Complutense de Madrid, E-28040 Madrid, Spain. alcaideb@quim.ucm.es
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't