4-Alkyl-2,5,7-cyclooctatrienols with high enantiomeric purities (93-96% ee), obtained by an improved copper-phosphoramidite-catalyzed addition of dialkylzinc reagents to cyclooctatetraene monoepoxide, have been subjected to simple and practical manipulations. Simple esterification reactions are able to deliver new functionalized isomeric 8-alkyl-7-acyloxybicyclo[4.2.0]octa-2,4-dienes through a domino sequence of rearrangement reactions, in good yields. Moreover, new 4-alkyl-substituted-2,6-cyclooctadienones with high optical purity can be efficiently obtained from gramscale reactions by simple thermal treatment. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).
Simple Synthetic Transformations of Highly Enantio-Enriched 4-Alkyl-2,5,7-cyclootatrienols into Functionalized Bicyclo[4.2.0]octa-2,4-dienes and 2,6-Cyclooctadienones
PINESCHI, MAURO;CROTTI, PAOLO;
2004-01-01
Abstract
4-Alkyl-2,5,7-cyclooctatrienols with high enantiomeric purities (93-96% ee), obtained by an improved copper-phosphoramidite-catalyzed addition of dialkylzinc reagents to cyclooctatetraene monoepoxide, have been subjected to simple and practical manipulations. Simple esterification reactions are able to deliver new functionalized isomeric 8-alkyl-7-acyloxybicyclo[4.2.0]octa-2,4-dienes through a domino sequence of rearrangement reactions, in good yields. Moreover, new 4-alkyl-substituted-2,6-cyclooctadienones with high optical purity can be efficiently obtained from gramscale reactions by simple thermal treatment. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
