405506-90-3Relevant academic research and scientific papers
Highly enantioselective proton-initiated polycyclization of polyenes
Surendra, Karavadhi,Corey
supporting information; experimental part, p. 11992 - 11994 (2012/09/08)
This report describes the synthesis of a range of chiral polycyclic molecules (tricyclic to pentacyclic) from achiral polyene precursors by enantioselective proton-initiated polycyclization promoted by the 1:1 complex of o,o′-dichloro-BINOL and SbCl5. Excellent yields (ca. 90% per ring formed) and enantioselectivety (20:1 to 50:1) were obtained. The process is practical as well as efficient, because the chiral ligand is both readily prepared from R,R- or S,S-BINOL and easily recovered from the reaction mixture by extraction.
Et2SBr.SbCl5Br: An effective reagent for direct bromonium-induced polyene cyclizations
Snyder, Scott A.,Treitler, Daniel S.
supporting information; experimental part, p. 7899 - 7903 (2010/04/02)
It's all about reactivity: Although bromonium-induced cation-π cyclizations are commonly utilized by nature to fashion six-membered rings from a diverse set of polyene precursors, no general laboratory method exists that can achieve the same breadth of substrate scope. An easily synthesized and handled reagent is described (see scheme) that is capable of directly, broadly, and rapidly effecting such reactions in good yield with a variety of geraniol, farnesol, and nerol derivatives.
Bio-inspired polyene cyclization: Synthesis of tetracyclic terpenoids promoted by steroidal acetal-SnCl4
Zhao, Yu-Jun,Loh, Teck-Peng
, p. 1434 - 1436 (2008/12/23)
This communication describes a highly efficient intermolecular polyene cyclization method using steroidal acetals as the initiators to synthesize tetracyclic terpenoids; both good yields and good asymmetric induction were obtained. The Royal Society of Chemistry.
Indium tribromide-promoted arene-terminated epoxy olefin cyclization
Zhao, Jun-Feng,Zhao, Yu-Jun,Loh, Teck-Peng
, p. 1353 - 1355 (2008/12/21)
An arene-terminated epoxy olefin cyclization was promoted by a water-tolerant Lewis acid to give tri- and tetracyclic 3β-hydroxy terpenoids and steroid derivatives in 57 and 37% yields, respectively, per new formed ring up to 75%. The Royal Society of Chemistry.
Regioselective palladium-catalyzed alkylation of allylic halides with benzylic Grignard reagents. Two-step synthesis of abietane terpenes and tetracyclic polyprenoid compounds
Rosales, Viale,Zambrano, Jorge L.,Demuth, Martin
, p. 1167 - 1170 (2007/10/03)
A highly regioselective palladium-catalyzed α-alkylation of allylic bromides 1a,c-e and chloride 1b with substituted and unsubstituted benzylic Grignard reagents is reported. The resulting alltrans polyenehomobenzene derivatives were obtained in excellent yields and regioselectivity. These products were easily converted to abietane-type diterpenes (10-12) and tetracyclic polyprenoid compounds (13, 14) through a Lewis acid-promoted cascade polyene cyclization reaction.
