Chemistry of 1-(dimethylamino)ethylidene and α-(dimethylamino)benzylidene acetals: utility as blocking group for diols and for selective esterification.
✍ Scribed by S. Hanessian; E. Moralioglu
- Book ID
- 104247491
- Publisher
- Elsevier Science
- Year
- 1971
- Tongue
- French
- Weight
- 211 KB
- Volume
- 12
- Category
- Article
- ISSN
- 0040-4039
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✦ Synopsis
In connection with our studies involving the synthetic utility of amide halides and amide acetals in carbohydrate&n general and nucleosides2 in particular, we report on some novel aspects of the synthetic applications of dimethyl acetals of ( 1) N,N-dimethylacetamide 3 and (2) benzamide4. Methyl 8-g-ribofuranoside' (3) was chosen as a model because it contains a cis diol group and a primary hydroxyl group, structural features suitable for chemical transformations and also found in the biologically important ribonucleosides. Treatment of 2 with two equivalents of J_ in a chlorinated hydrocarbon such as 1,1,2_trichloroethane 6 at room temperature for one hour in the dark affords the corresponding methyl 2,3-~~l-(dimethylamino)ethylidene]-B-~-ribofuranoside 4 as a 2:l mix-