Linked Life Data

11960455

Source:http://linkedlifedata.com/resource/pubmed/id/11960455

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
2002-4-18
pubmed:abstractText
The potent immunosuppressive agent (-)-sanglifehrin A (5), initially discovered in a soil sample from Malawi, has been synthesized in a highly convergent and stereocontrolled manner. The enantioselective approach relies on initial construction of the iodovinyl carboxylic acid 14, which is coupled to tripeptide 59 in advance of a key macrolactonization step that generates 61a. An alternative protocol that involves the linkage of 14 to 46 for possible construction of the large ring failed due to an inability to bring about a corresponding macrolactamization maneuver. An efficient means for elaborating the C26-N42 spirolactam western sector of 5 is also detailed. This requisite fragment was assembled through the proper adaptation of consecutive aldol tactics for construction of the nine stereogenic centers, six of which are contiguous. The first aldol process consisted of the tin triflate-mediated reaction of the aldehyde derived from 72 with enantiopure ketone 73 to generate the syn C36-C37 relationship resident in 75. Once the conversion of 75 to 78 had been completed, the attachment to ketone 66 was effected with (+)-DIPCl, thereby setting the C33-C34 relationship as anti. Once functional group modifications had given rise to 62, spirolactamization was achieved to deliver predominantly 94, thereby setting the stage for the acquisition of vinyl stannane 13 and its subsequent palladium-catalyzed Stille coupling to 61b. Controlled acidic hydrolysis completed the synthesis of 5. Other important features of the present route are addressed where relevant.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0002-7863
pubmed:author
pubmed:issnType
Print
pubmed:day
24
pubmed:volume
124
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4257-70
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
A convergent three-component total synthesis of the powerful immunosuppressant (-)-sanglifehrin a.
pubmed:affiliation
Evans Chemical Laboratories, The Ohio State University, Columbus, Ohio 43210, USA. paquette.l@osu.edu
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't