Amino-de-hydroxylation

Replacement of a Hydroxy by an Amino Group Amino-de-hydroxylation... 

Monoazide a- and p-cyclodextrins 77a-b were easily obtained from the corresponding monohydroxy cyclodextrins 63a-b. When submitted to DIBAL-H, the azide is reduced first. Aluminum derivatives complexed on the formed amide create steric hindrance, which directs the following de-O-benzylation toward the farthest position [74] (Scheme 9.36) as in the case of monohydroxy cyclodextrin 63a (Scheme 9.30 and Scheme 9.31). For a-cyclodextrin, the farthest position is 6D, which leads to the 6A-amino,6D-hydroxyl regioisomer 78a in 74% yield. For P-cyclodextrin, a molecular model study revealed that the farthest position is 6E, leading to the formation of the 6A-amino,6E-hydroxyl regioisomer 78b in 89% yield. It has to be noted that this pattern of differentiation is the same as for 6A-hydroxyl,6D-azido cyclodextrins 43a-b (Scheme 9.18). 

According to the H-NMR spectra in DMSO - de, benzodiazepine 69 exists as a 4 1 mixture of tautomers A and A. Benzodiazepin-2-one 69 is formed due to the substitution of the hydroxyl group of coiunarin 67 by one of the amino groups of o-phenylenediamine and the C - O bond cleavage in the py-rone ring upon reaction with the second amino group. 

Umsetzung von 1-Brom-alkanen mit N-Benzyl-hydroxylamin in Phosphorsaure-tris-[di-methylamid] (HMPT), Dehydratisierung des so gebildeten N-Alkyl-N-benzyl-hydroxyl-amins mit 2-Fluor-l-methyl-pyridinium-(4-methyl-benzolsulfonat) und saure Hydrolyse des entstandenen N-Benzyliden-amins ergibt 1-Amino-alkane in guten Ausbeuten3. 

Replacement of an Amino Group by a Hydroxyl Group Hydroxy-de-amination... 

Migrations of Halogen, Hydroxyl, Amino, etc. Hydroxy-de-bromo-c/ne-substitution, etc. 

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