Effect of ring fusion stereochemistry on double bond geometry. Unexpected formation of nine-membered cyclic ether with E-configurated double bond through RCM
作者:Subrata Ghosh、Md. Firoj Hossain、Chanchal K. Malik、Soumitra Maity
DOI:10.1016/j.tet.2010.09.084
日期:2010.11
ether with E-configurated doublebond was observed during construction of 5-9-5 tricycles through RCM of dienes. Ring fusion stereochemistry in the products oxonenes was found to have profound influence on the olefin geometry. cis-anti-cis 5-9-5 tricycle was obtained with Z-configurated olefin while cis-syn-cis 5-9-5 system was obtained with E- as well as Z-configurated doublebond with the former predominating
A new approach to A/B ring analogue of eleutherobin and sarcodictyns through a sequence of highly diastereofaceselective Diels–Alder reaction and ring opening–ring closing metathesis (RO–RCM)
作者:Chanchal K. Malik、Md. Firoj Hossain、Subrata Ghosh
DOI:10.1016/j.tetlet.2009.04.033
日期:2009.6
An approach to the construction of A/B ring analogue of antitumour compounds eleutherobin and sarcodictyns is described. The key steps involve a highly diastereofaceselective Diels–Alder reaction of a dienophile containing a furanosugar moiety with cyclopentadiene and ring opening–ring closingmetathesis of the resulting adduct.