90899-10-8Relevant articles and documents
Polyfunctionalised Cyclohexanes from Dianhydrodeoxyinositols. cis-Deoxy-1,3(1,4)-inosadiamines from Benzene
Kuehlmeyer, Rainer,Keller, Reinhold,Schwesinger, Reinhard,Netscher, Thomas,Fritz, Hans,Prinzbach, Horst
, p. 1765 - 1800 (2007/10/02)
A ca. 9 : 1 mixture (yield 87 - 90percent) of the stereoisomeric (1α,2α,6α)-/(1α,2β,6α)-2-bromo-7-oxa-bicyclohept-3-enes (7a/8a) is obtained via controlled NBS bromination of 4,5-epoxycyclohexene (5). 7a/8a are quantitatively equilibrated in the presence of tetraalkylammonium bromides (the equilibrium being controlled by the polarity of the solvent (3 : 7 in acetonitrile) and are isolated pure by chromatography.Through selective halogen substitution (7b/8b, 9b - d/10b - d) and ammonolysis the allylic epoxy alcohols 9a/10a are obtained in high yields.Stereospecific epoxidation of 7a/8a yields the (1α,2α,3α,5α,7α)-/(1α,2β,3α,5α,7α)-diepoxy bromides 12a/14a.The latter are equilibrated quantitatively to mixtures favoring either one in the ratio of ca. 9 : 1 (CCl4) and 1 : 9 (CH3CN), respectively.Upon SN2 substitution with ammonium acylates (-> 13b, c/15b, c) and ammonolysis the naturally not occurring dianhydrodeoxyinositols 13a/15a are isolated in practically quantitative yields.The usefulness of 13a/15a and of various derivatives for the stereoselective synthesis of cis-1,4- and cis-1,3-disubstituted cyclohexanetriols is exemplified by reactions with monovalent (H2O, HI, NaN3) and divalent nucleophiles (NH2NH2, CH3NHNH2).I.a. the cis-deoxy-1,3-inosadiamines 1 (2-deoxystreptamine)/2 and the cis-deoxy-1,4-inosadiamines 3/4 become available in high yields.