Journal article
A Silicon Tether Approach for Addition of Functionalized Radicals to Chiral α-Hydroxyhydrazones: Diastereoselective Additions of Hydroxymethyl and Vinyl Synthons
Journal of organic chemistry, Vol.69(3), pp.863-875
02/06/2004
DOI: 10.1021/jo035405r
PMID: 14750816
Abstract
Stereocontrolled additions of hydroxymethyl and vinyl groups to chiral α-hydroxyhydrazones can be achieved by radical cyclizations using bromomethyl or vinyl radical precursors tethered via a temporary silicon connection. Tin-mediated 5-exo radical cyclization of α-hydroxyhydrazones using a silicon-tethered bromomethyl group, followed by oxidative removal of the tether, provides anti-2-hydrazino 1,3-diols in good yield. Tandem thiyl radical addition−cyclization of α-hydroxyhydrazones using a silicon-tethered vinyl group, followed by treatment with potassium fluoride, affords acyclic allylic anti-hydrazino alcohols in good yield. The thiyl addition−cyclization method has been successfully extended to the use of α,β-dihydroxyhydrazones without prior protection or hydroxyl differentiation. Diastereoselection in both reaction types increases with increasing A values of the appended groups, consistent with prediction by the Beckwith−Houk model for stereocontrol in 5-hexenyl radical cyclizations.
Details
- Title: Subtitle
- A Silicon Tether Approach for Addition of Functionalized Radicals to Chiral α-Hydroxyhydrazones: Diastereoselective Additions of Hydroxymethyl and Vinyl Synthons
- Creators
- Gregory K FriestadSara E Massari
- Resource Type
- Journal article
- Publication Details
- Journal of organic chemistry, Vol.69(3), pp.863-875
- DOI
- 10.1021/jo035405r
- PMID
- 14750816
- NLM abbreviation
- J Org Chem
- ISSN
- 0022-3263
- eISSN
- 1520-6904
- Publisher
- American Chemical Society
- Language
- English
- Date published
- 02/06/2004
- Academic Unit
- Chemistry
- Record Identifier
- 9983985969102771
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