ISSN:
0170-2041
Keywords:
Glycals, C-2 lithiation of
;
α-Alkoxyvinyl phenyl sulfoxides, β-C lithiation of
;
β-Alkoxy acrylates, β-C lithiation of
;
β-Hydroxymethylvinyl phenyl sulfoxides, transformation into α-methylene carbonyl derivatives
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Treatment of glycopyranosyl phenyl sulfoxides 2ah, 1, 2bh, 1 with two equivalents of lithium diisopropylamide provides directly the C-2-lithiated glycal intermediates 3aAh, 1, 3bAh, 1 which, on reaction with formaldehyde as electrophile, furnish the 2-hydroxymethyl derivatives 4ah, 1 and 4bh, 1, respectively. These compounds are transformed at elevated temperature and by acid catalysis directly into the α-methylene-δ-lactones 5a, b. Correspondingly, from 2ah, 1 and methyl chloroformate as electrophile the 2-methoxycarbonyl derivatives 6h and 61, respectively, are obtained. Treatment of 6h, 1 with Raney nickel leads to 2-methoxycarbonyl-substituted glycal 7 containing a β-alkoxyacrylate moiety which again can be directly β-C-lithiated as demonstrated by the introduction of deuterium at C-1.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.199119910187
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