Treatment of tetrahydropyranyl (or tetrahydrofuranyl) ether of allylic alcohol with tributylmanganate provided 7-octene-1,5-diol (or 6-hepten-1,4-diol) in good yields. The reaction of propargylic tetrahydropyranyl ether with tributylmanganate is also described.
Intra- and intermolecular reactions of carbon-centered radicals generated by photolysis of organoindium compounds were examined. The photolysis of vinylindium compounds and indium acetylides provided vinyl and alkynyl radicals, respectively, which were trapped with ethyl iodoacetate giving the corresponding beta,gamma-unsaturated esters. Allylic indium compounds, prepared from 8-bromo- or 8-iodooct-1,6-dienes and powdered indium metal, underwent an intramolecular radical cyclization to afford the 5-exo-trig product. (c) 2008 Elsevier Ltd. All rights reserved.
Formation of manganese–alkyne complexes mediated by trialkylmanganates and their application
Treatment of dodec-6-yne with triallylmanganate in the presence of 1,3,5-trimethylbenzene provides (Z)-dodec-6-ene. An addition of D2O before quenching the reaction affords the corresponding dideuterated alkene. The result suggests the existence of the manganese-alkyne complex as an intermediate. Treatment of methyl propargyl ethers as alkynes with tributylmanganate generates propargylmanganese species. The reaction of non-2-ynyl tetrahydropyran-2-yl ether with tributylmanganate provides tetradec-7-yn-1,5-diol and 6-hexylocta-6,7-dien-1,5-diol. (C) 2003 Elsevier Ltd. All rights reserved.
Use of Allyl, 2-Tetrahydrofuryl, and 2-Tetrahydropyranyl Ethers as Useful C3-, C4-, and C5-Carbon Sources: Palladium-Catalyzed Allylation of Aldehydes
to excellent yields with high levels of stereoselectivity. Useful C3-unit elongation, which makes the best use of an allylether as a protecting group and a nucleophilic allylation agent, is demonstrated. Mechanisms for the umpolung reaction (of an allylether into an allylic anion) and stereoselectivity associated with allylation of aldehydes are discussed.