1.
Org Lett
; 3(13): 2001-4, 2001 Jun 28.
Article
in English
| MEDLINE
| ID: mdl-11418034
ABSTRACT
[reaction: see text] Pestalotiopsin A is a structurally unique caryophyllene-type sesquiterpene which has shown immunosuppressive activity and cytotoxicity in preliminary assays. A stereocontrolled approach to the functionalized 2-oxabicyclo[3.2.0]heptane core of pestalotiopsin A is described. The approach includes a samarium(II)-mediated 4-exo-trig cyclization and a trans-lactonization process triggered by the addition of alkylytterbium reagents to a cyclobutanone intermediate.