Synthetic approaches to 11-deoxyhomoprostacyclin analogues
Abstract
A number of synthetic approaches to the title compounds are described. The key synthetic intermediates, the allylcyclopentanone (4) and the methoxyallylcyclopentanone (30) have been prepared from cyclopent-2-enone using the organocuprate conjugate-addition–enolate-alkylation reaction. The selective functionalisation of the allylic double bond in the ketone (4) and protected derivatives of the alcohol (7) has been attempted using bromine in acetic acid, N-bromosuccinimide in aqueous dimethyl sulphoxide, and iodine–silver chromate. A number of interesting observations made during these investigations are reported. A successful synthesis of Z- and E-11-deoxyhomoprostacyclin (2) and (3) from the methoxyallylcyclopentanone (30) is described.