Diazomethane → O-Benzoylhydroxylamine

HRID 487367Notes

Reaction equation

HRID 487367 reaction equation
O(O)O.[N+](=C)=[N-].ON=[N+]=[N-].N([Si](C)(C)C)=[N+]=[N-].[C:18]([O:26][N:27]=[N+]=[N-])(=[O:25])[C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1>CO.[Cl-].[Zn+2].[Cl-]>[C:18]([O:26][NH2:27])(=[O:25])[C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1

Participants

8

Reactant 5

HCID 9550DiazomethaneHCID 78378AzidotrimethylsilaneHCID 166717TrioxidaneHCID 18670949Hydroxy azide2×HCID 57299698Azido benzoate

Product 1

HCID 191324O-Benzoylhydroxylamine

Reagents, catalysts & solvents 2

HCID 3007855ZincchlorideCatalystHCID 887MethanolSolvent

Procedure

Phenylacetylene is subject to 1) hydroxymethylation followed by 2) Lindlar reduction to yield cis-cinnamyl alcohol. ##STR6## 3) The cis-cinnamyl alcohol is subjected to the titanium-catalyzed epoxidation process to yield (2S,3R)-epoxy alcohol. ##STR7## 4) This epoxy alcohol is oxidized with RuCl3 and NaIO4, and 5) the reaction product converted to the methyl ester of the epoxide with ethereal diazomethane. 6) This methyl ester of the epoxide is transformed into the desired hydroxyazide by epoxide cleavage using azidotrimethylsilane and a catalytic amount of zinc chloride followed by acid hydrolysis. ##STR8## 7) The hydroxy azide is transformed into azido benzoate and hydrogenated in methanol to produce amino benzoate. 8) The amino benzoate is rearranged to give the product. ##STR9## Modifications in this method have also been described by Denis, J. N. et al., "An Improved Synthesis of the Taxol Side Chain and of RP56976", J. Org. Chem 55, 1957-1959 (1990).

Sources & evidence

ORD record
ord-b96380cebd754560b1493c7a3b2468df
Source dataset
uspto-grants-1994_03
Patent number
US05294737

Reaction notes

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