Access to a new family of medium ring aromatic lactones
摘要:
We report a new method for preparation of hydroxyacids as precursors of benzolactones using a simple and an efficient electrochemical step. This gives in only four steps six- to eleven-membered lactones with high isolated yields from conveniently substituted aryl bromides. The lactonisation was performed according to the Yamamoto's process. (c) 2006 Elsevier Ltd. All rights reserved.
Access to a new family of medium ring aromatic lactones
摘要:
We report a new method for preparation of hydroxyacids as precursors of benzolactones using a simple and an efficient electrochemical step. This gives in only four steps six- to eleven-membered lactones with high isolated yields from conveniently substituted aryl bromides. The lactonisation was performed according to the Yamamoto's process. (c) 2006 Elsevier Ltd. All rights reserved.
A synthetic approach to ring-D aromatic steroids, viz. 5, based on a cascade of radical-mediated cyclisations from the orthoaryl-substituted iododienynones 12 and 13, instead led to the macrocyclic ketone 16 or to the novel, bridged tricycle 17, respectively, as the major products.
Cascade radical-mediated cyclisations with conjugated ynone electrophores. An approach to the synthesis of steroids and other novel ring-fused polycyclic carbocycles
作者:Gerald Pattenden、Davey A. Stoker、Nicholas M. Thomson
DOI:10.1039/b703373g
日期:——
A cascade radical-mediated Diels-Alder reaction with the iododienynone 16b produced the tricyclic ketone 17 (22%). By contrast, treatment of the substituted furans 36 and 47 with Bu(3)SnH-AIBN, instead led to the tetracycles 44 and 58 respectively, rather than the anticipated oestranes, i.e. 38 and 48. In a separate study, attempted cascade radical-mediatedcyclisations from the ortho-aryl substituted