2-Amino-2-deoxytetrose Derivatives. Preparation from 4,5-Dihydroisoxazoles via Reductive Cleavage
The 4-alkoxy-3-nitro-4,5-dihydroisoxazoles 2a,b were prepared by condensation of nitromethane and chloroacetaldehyde, protection of the resulting nitroaldol Ic, and subsequent nitrosative cyclization. Multistep replacement of the nitro group of 2a,b by a 2-(1,3-dithiolanyl) group gave 7a,b. Reaction...
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Published in | Journal of organic chemistry Vol. 60; no. 20; pp. 6302 - 6308 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
WASHINGTON
American Chemical Society
01.10.1995
Amer Chemical Soc |
Subjects | |
Online Access | Get full text |
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Summary: | The 4-alkoxy-3-nitro-4,5-dihydroisoxazoles 2a,b were prepared by condensation of nitromethane and chloroacetaldehyde, protection of the resulting nitroaldol Ic, and subsequent nitrosative cyclization. Multistep replacement of the nitro group of 2a,b by a 2-(1,3-dithiolanyl) group gave 7a,b. Reaction of 7b with lithium borohydride afforded reductive cleavage of the dihydroisoxazole ring to produce the open-chain diastereomeric amino alcohols 6a,b. A reproducible ratio of > 90: 10 6a/6b was obtained using freshly prepared hydride reagent. The amino alcohols were converted to the corresponding (R*,R*)-amide 6c and (R*,S*)-amide 6d which were chromatographically separated. The(R*,R*)-amide was transformed into the 2-amino-2-deoxythreose derivatives 11a,b and hence to 12 while the (R*,S*)-amide was similarly transformed to 2-amino-2-deoxyerythrose derivative 14a and its anomeric isomer 14b. |
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Bibliography: | istex:D1C6A2826F00687AD9D814993DF0317814F184C9 ark:/67375/TPS-M012CTB0-B |
ISSN: | 0022-3263 1520-6904 |
DOI: | 10.1021/jo00125a015 |