Synthesis of a Novel Sesquiterpene Isolated from the Pheromone Gland of a Stink Bug, Tynacantha marginata Dallas
摘要:
A novel sesquiterpene, isolated as the putative sex pheromone of a stink bug (Tynacantha marginata Dallas) and proposed to have an unprecedented carbon framework, was synthesized as its racemate by using an intramolecular double Michael cyclization as the key step. Comparison of the spectral data of the synthetic sample with those of the natural material confirmed the proposed structure. (C) 2000 Elsevier Science Ltd. All rights reserved.
Synthesis of a Novel Sesquiterpene Isolated from the Pheromone Gland of a Stink Bug, Tynacantha marginata Dallas
摘要:
A novel sesquiterpene, isolated as the putative sex pheromone of a stink bug (Tynacantha marginata Dallas) and proposed to have an unprecedented carbon framework, was synthesized as its racemate by using an intramolecular double Michael cyclization as the key step. Comparison of the spectral data of the synthetic sample with those of the natural material confirmed the proposed structure. (C) 2000 Elsevier Science Ltd. All rights reserved.
Diastereoselective double michael additions of vinylogous esters and thexyldimethylsilyl triflate-induced cyclizations
作者:Dieter Schinzer、Markus Kalesse
DOI:10.1016/s0040-4039(00)92283-4
日期:1991.1
Double Michael additions of vinylogous esters of type 1 with crotyl ester generates diastereoselectively bicyclo[2.2.2]octanone 2 with four defined chiral centers via a synclinal transition state. Thexyldimethylsilyl enol ethers of type 5 and 10 undergo smooth cyclization to bicyclo[3.3.1]nonenones 7 and bicylo[3.3.0]octenones 12 by addition of Lewis acids.
Silica gel-catalyzed cyclizations of mixed ketene acetals
作者:Dieter Schinzer、Markus Kalesse、Jazid Kabbara
DOI:10.1016/s0040-4039(00)80726-1
日期:1988.1
Mixed ketene acetals of type undergo smooth cyclization upon treatment with silica gel yielding diastereoselectively bicyclo[2.2.2]octanones of type . Alternatively, the same result was obtained by exposure of the substrates to TiCl4 at low temperature.