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Acetyl group regioselective acetylation

The primary OH group can be selectively blocked by the bulky triphenyl-methyl (trityl) moiety, followed by esterification at the secondary OH groups and removal of the protecting trityl group. Thus 2,3-di-O-acetyl cellulose has been obtained by this procedure. Moreover, regioselectively substituted mixed cellulose esters, acetate/propionate, were prepared by subsequent acy-... [Pg.137]

Removal of the silyl protecting group using TBAF, and subsequent acetylation, led to the diacetate 818. Regioselective nitration and catalytic hydrogenation provided the (R)-arylamine 814 (613) (Scheme 5.95). [Pg.253]

Regioselective deacylation has also been observed189 in the acid-catalyzed transesterification of some 3, 5 -di-0-acetyl-2 -deoxy-2 -halo-uridines in methanol to give the corresponding 3 -0-acetyl derivatives in yields of 36-66%. The presence of the 2-halogen substituent seems essential for the selectivity in the case of 2, 3, 5 -tri-0-acetyl-uridine, no significant differences in the reaction rates of the acetyl groups towards transesterification were apparent. [Pg.41]

See other pages where Acetyl group regioselective acetylation is mentioned: [Pg.101]    [Pg.81]    [Pg.160]    [Pg.95]    [Pg.318]    [Pg.136]    [Pg.312]    [Pg.123]    [Pg.137]    [Pg.140]    [Pg.569]    [Pg.592]    [Pg.61]    [Pg.36]    [Pg.59]    [Pg.63]    [Pg.183]    [Pg.249]    [Pg.21]    [Pg.46]    [Pg.383]    [Pg.329]    [Pg.583]    [Pg.259]    [Pg.270]    [Pg.796]    [Pg.72]    [Pg.220]    [Pg.13]    [Pg.17]    [Pg.493]    [Pg.161]    [Pg.381]    [Pg.118]    [Pg.245]    [Pg.40]    [Pg.40]    [Pg.133]    [Pg.19]    [Pg.264]    [Pg.354]    [Pg.494]    [Pg.300]    [Pg.155]    [Pg.161]    [Pg.101]    [Pg.76]    [Pg.455]   
See also in sourсe #XX -- [ Pg.51 , Pg.52 , Pg.53 , Pg.54 ]



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Acetyl group

Acetylation regioselective

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