(−)-Astrogorgiadiol: a shorter route to A-ring synthon
摘要:
A new route to the key A-ring/C-ring precursor synthon of (-)-astrogorgiadiol is described, for the strategy based on Robinson annulation. This synthon is also key for the synthesis of other related calicoferols and astrogorgols. The route takes full advantage of the opening of 6-methoxy-1-tetralol with bis(sym-collidine) bromine(I) triflate. It involves a new protection-deprotection sequence of an enone. It is the shortest synthesis to date, consisting of seven steps. (C) 2013 Elsevier Ltd. All rights reserved.
Formation of Spirocyclic Compounds from Heck Cyclizations Invoking Cyclic Enamides
作者:Gedu Satyanarayana、Martin E. Maier
DOI:10.1021/jo800650e
日期:2008.7.1
(2-bromophenyl)ethyl substituent in the 5-position produces spirocyclic products, imides 14 and amides 15. The formation of these products can be explained by insertion of the enamide double bond into the initial aryl−Pd bond followed by oxidation or reduction of the organopalladium intermediate. Alternatively, formation of these spiro compounds might proceed via acyliminium ion intermediates.
Bis(sym-collidine)bromine(I) hexafluorophosphate as oxidant
作者:Gérard Rousseau、Sylvie Robin
DOI:10.1016/s0040-4039(00)01598-7
日期:2000.11
Primary and secondary alcohols in solution in methylene chloride are oxidised with bis(sym-collidine)bromine(I) hexafluorophosphate in good yields to the carbonylcompounds. For secondary and tertiary alcohols in which one of the substituents is a 4-methoxyphenyl group the oxidation takes place by cleavage of the phenyl-sp3 carbon bond and formation of bromoanisole and carbonylcompounds.
(−)-Astrogorgiadiol: a shorter route to A-ring synthon
作者:Guillaume Médard
DOI:10.1016/j.tet.2012.12.087
日期:2013.3
A new route to the key A-ring/C-ring precursor synthon of (-)-astrogorgiadiol is described, for the strategy based on Robinson annulation. This synthon is also key for the synthesis of other related calicoferols and astrogorgols. The route takes full advantage of the opening of 6-methoxy-1-tetralol with bis(sym-collidine) bromine(I) triflate. It involves a new protection-deprotection sequence of an enone. It is the shortest synthesis to date, consisting of seven steps. (C) 2013 Elsevier Ltd. All rights reserved.