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Syntheses of Amino‐dideoxyallose and Amino‐deoxyribose Derivatives Using Acylnitroso Dienophiles
Author(s) -
Defoin Albert,
Fritz Hans,
Geffroy Guillaume,
Streith Jacques
Publication year - 1988
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19880710709
Subject(s) - chemistry , hydrogenolysis , stereospecificity , cycloaddition , stereochemistry , pyranose , deoxyribose , adduct , isostere , anomer , anomeric effect , organic chemistry , nucleic acid , catalysis , biochemistry
Abstract The dimethyl acetals 4 of (E) ‐2,4‐pentadienal and of ( E , E )‐ and ( E , Z )‐2,4‐hexadienals undergo regio‐ and stereospecific cycloaddition reactions with in ‐ situ ‐generated acylnitroso dienophiles 5a and 5b , leading thereby to the corresponding dihydrooxazines 7a–d and 8c–d . cis ‐Glycolization of these latter adducts stereospecifically gave the dihydro derivatives 9a–d and 10d which, after sequential hydrogenolysis, deacetalization, and instant cyclization, led to the aminodeoxyribose derivatives 17a, 17f , and 18 , and to the amino‐dideoxyallose compounds 17c and 17h . These piperidino‐deoxysugar derivatives exhibit a strong anomeric effect, i.e. OHC(1) is always axial, which is explained in terms of a n N (π)‐σ*(COH) orbital compression, as compared to the less pronounced one in the more classical pyranose series.