THE OLEFIN SYNTHESIS FROM BETA-HYDROXYALKYLPHOSPHONATES INDUCED BY FLUORIDES OR RELATIVELY WEAK BASES

Citation
T. Kawashima et al., THE OLEFIN SYNTHESIS FROM BETA-HYDROXYALKYLPHOSPHONATES INDUCED BY FLUORIDES OR RELATIVELY WEAK BASES, Bulletin of the Chemical Society of Japan, 71(1), 1998, pp. 209-219
Citations number
43
Categorie Soggetti
Chemistry
ISSN journal
00092673
Volume
71
Issue
1
Year of publication
1998
Pages
209 - 219
Database
ISI
SICI code
0009-2673(1998)71:1<209:TOSFBI>2.0.ZU;2-1
Abstract
beta-Hydroxyalkylphosphonates, which were prepared readily from alkylp hosphonates and carbonyl compounds, were treated with a fluoride ion s uch as CsF or with relatively weak bases such as K2CO3 in N,N-dimethyl formamide to give the corresponding olefins in good yields. One molar equivalent of water to bases is effective for increasing the yields of olefins. The stereochemistry of erythro-dimethyl (2-hydroxy-1-methyl- 2-phenyl)ethylphosphonate was determined by X-ray crystallographic ana lysis. Use of threo-isomer gave (E)-olefin exclusively, while that of erythro-enriched isomer afforded predominantly (Z)-olefin, indicating that the present olefination proceeds stereospecifically in a manner o f syn-elimination.