ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The benzyl- and the acyl-protected glyconolactone tosylhydrazones 6, 9, 12, 16, and 19 (Scheme 1) were prepared in good yields by treating the hemiacetals 4, 7, 10, 14, and 17 with N-tosylhydrazine, to give the N-glycosylhydrazines 5, 8,11,15, and 18, and by oxidizing these hydraz tries with N-bromosuccinimide (NBS) in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), with CrO3-dipyridine complex or with pyridinium dichromate. Photolysis of the sodium sail 20 of 6 (Scheme 2) in the presence of N-phenylmaleimide, dimethyl fumarate, or acrylonitrile gave the corresponding cyctopropanes 21-28 in satisfactory yields. Phololytic or thermolytic glycosidation of phenol and 4-melhoxyphenol by 20 yielded the anomeric glycosides 29/30 and 31/32, yields being marginally higher for the Ihermolytic process. Phololytic glycosidation of propan-2-ol gave the glycosides 33 and 34 in low yields only. Yields and ratios of products were compared to those obtained with the diazirine 1 as a source of glycosylidene carbenes. While the yields from 20 are lower, the ratios of products obtained in the photolytic reactions are in agreement with the formation of a common intermediate from both carbene precursors.
Additional Material:
2 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19910740845
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