97747-53-0Relevant articles and documents
Synthesis of 1,2,3-triazoles from azide-derivatised aminocyclitols by catalytic diazo transfer and CuAAC click chemistry
Ji, Li,Zhou, Guo-Quan,Qian, Chao,Chen, Xin-Zhi
, p. 3622 - 3636 (2014/06/23)
CuII-catalysed diazo transfer and CuI-catalysed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) "click chemistry" were used to synthesis C7N aminocyclitol-derivatised 1,2,3-triazoles. In the course of this work, the -N=N- moiety was transferred onto C7N aminocyclitols such as validamine, valienamine and valiolamine by employing imidazole-1-sulfonyl azide as the diazo transfer reagent with catalysis by CuII, ZnII and NiII, in moderate to good yields. The obtained azidocyclitols were coupled with various terminal alkynes under modified Meldal's conditions with good to excellent yields. The stereo- and regiochemistry of the products were confirmed by 2D-NMR (NOESY and HMBC). One-pot syntheses of the corresponding 1,2,3-triazoles, as safer and more efficient procedures, were also investigated and gave moderate to good yields. Copyright
Synthetic strategies directed towards 5a-carbahexopyranoses and derivatives based on 6-endo-trig radical cyclizations
Gomez, Ana M.,Uriel, Clara,Company, Maria D.,Lopez, J. Cristobal
, p. 7116 - 7132 (2012/01/06)
Several synthetic strategies directed towards 5a-carbahexopyranoses and based on 6-endo-trig radical cyclization of unsaturated carbohydrate derivatives have been devised. Three elements for regiocontrol to optimize the 6-endo/5-exo ratio have been incorporated, and their efficiencies in directing 6-endo cyclizations have been evaluated. These elements - namely: i) the incorporation of a substituent at C-5 (radical numbering), ii) the use of a vinyl (rather than alkyl) radical, and iii) the inclusion of ring strain in the system - have proved useful when used in combination. The simultaneous presence of two of them also results in 6-endo selectivity. On another topic, the ozonation of the ensuing alkenylstananes to afford diols seems to be based on a tin-oxygen rearrangement, similar to that reported for related vinylsilanes, rather than on remarkable stabilities of tin-containing primary ozonides as we had previously suggested.
TOTAL SYNTHESIS OF (+)-(1,2,3/4,5)-2,3,4,5-TETRAHYDROXYCYCLOHEXANE-1-METHANOL AND (+)-(1,3/2,4,5)-5-AMINO-2,3,4-TRIHYDROXYCYCLOHEXANE-1-METHANOL . X-RAY CRYSTAL STRUCTURE OF (3s)-(+)-2-EXO-BROMO-4,8-DIOXATRICYCLO3,7>NONA
Ogawa, Seiichiro,Iwasawa, Yoshikazu,Suami, Tetsuo,Ohba, Shigeru,Ito, Masatoki,Saito, Yoshihiko
, p. 903 - 906 (2007/10/02)
The optical resolution of (+/-)-7-endo-oxabicyclohept-5-ene-2-carboxylic acid (+/-)-1 has been accomplished by use of (R)-(+)- and (S)-(-)-α-methylbenzylamine, respectively.The absolute configuration of (-)-(1) has been determined on the basis of X