
horner-wadsworth-emmons praticharya

horner-wadsworth-emons (hetch. vii. ii) praticharya anedi aldehydes (ledhaa keatonelu) thoo sthirapadina phosphonate carbonianla sendriya rasayana saastramlo pradhanamgaa ii-alkenlanu utpatti cheyadaaniki upayoginche rasayana praticharya.
1958loe, leopold horner phosphonate-sthireekarinchina carbonianlanu upayoginchi savarinchina whittig praticharyanu prachurinchaadu. vilium ess. wadsworth mariyu vilium dii. immons pratispandananu marinta nirvachinchindi.
whittig praticharyalo upayoginche phosphonium yilaidlaku viruddhamgaa, phosphonate-sthireekarinchina carbonianlu ekkuva nucleophilic conny takkuva basic. adevidhamgaa, phosphonate-sthireekarinchina carbonianlanu alkylated cheyavachu. phosphonium yilides maadirigaa kakunda, dialcalphosphate uppu upa utpattini jaleeya velikiteeta dwara sulabhamgaa tolaginchavacchu.
aneka sameekshalu prachurinchabaddaayi.
praticharya vidhanam.
horner-wadsworth-emons praticharya phosphonate carbonian 1nii ivvadaaniki phosphonate yokka deprotonationtho praarambhamavutundi. 3a ledhaa 3bnii utpatti chese aldehyde 2 (ledhaa keaton) paie carbonian yokka nucleophilic jodimpu raetu-parimiti dasha. r2 = h ayithe, appudu madhyavartulu 3a mariyu 4a mariyu madhyavartulu 3b mariyu 4b okadaanitoe okati parasparam marchukovacchu. oxphosphaten 4a mariyu 4b digubadi ("e")-alkeen 5 mariyu ("z")-alkeen 6 yokka tudi tolagimpu, upa utpatti dialkyl-fasfate.
alkeen isomers 5 mariyu 6 nishpatti prarambha carbanian jodimpu yokka stereochemical phalitam mariyu madhyavartula samatulyata saamardhyampai aadharapadi undadu.
tudi tolagimpu jaragadaniki phosphonate kuu electron-droying group (eedablyoojee) alfa avasaram. electron-droying group lenappudu, tudi utpatti α-hydroxyphosphonate 3a mariyu 3b. ayithe, eee α-hydroxyphosphonatelnu disopropyl carbodymidetho praticharya dwara alkeenlugaa maarchavacchu.
stereoselectivity.
horner-wadsworth-emons praticharya ("ii")-alkeens erpadataaniki anukuulamgaa untundi. saadhaaranamgaa, madhyavartula madhya marinta samatulyata, ("ii")-alkeen erpadataaniki ekkuva empika.
pratyaamnaaya alkeenlu.
thampson mariyu heathcock vividha aldehydelatho methyl 2 (dimethylphosphono) acetate yokka praticharyapai kramabaddhamaina adhyayanam chesaaru. prati prabhavam chinnadi ayinappatikee, avi sanchita prabhavanni kaligi undi, phosphonate yokka nirmaanaanni savarinchakundaa stereochemical phalitaanni savarinchadam saadhyamaindi. vaaru eee krindi paristhithulatho ekkuva ("ii")-steroselectivityni kanugonnaruh
oka pratyeka adhyayanamlo, bhaarii phosphonate mariyu bhaarii electron-droying samuuhaalu ii-alkeen empikanu penchutaayani kanugonabadindi.
trisabstituted alkeenlu.
phosphonate mariyu electron-droying groupula yokka steric pedda bhaagam aliphatic aldehydelatho α-branch phosphonatela praticharyalo keelaka paatra poeshistumdi.
sugandha aldehydelu daadaapu pratyaekamgaa ("ii")-alkeneslanu utpatti chestaayi. sugandha aldehydela nundi ("z")-alkeenlu avasaramaite, sthira-genari savarananu (krinda chudandi) upayoginchavacchu.
keatonela yokka olephination.
keatonela horner-wadsworth-emons pratispandana yokka stereoselectivity takkuvagaa untundi.
vaividhyaalu.
bays sensitive substrates.
aneka uparitalaalu sodiyam hydrideku sthiramgaa lenanduna, telikapati sthaavaraalanu upayoginchi aneka vidhanalu abhivruddhi cheyabaddaayi. lithium chloride mariyu dboo upayoginchi masamune mariyu roush telikapati paristhitulanu abhivruddhi chesaayi. rathke dheenini triathylamyntho lithium ledhaa magnitium haalaidlaku vistarinchaadu. aneka itara sthaavaraalu prabhaavavantamgaa unnatlu kanugonabadindi.
inca maarpu.
doubleu. clark still mariyu sii. jennari adbhutamaina stereoselectivito "z"-aalkeenlanu ichhe paristhitulanu abhivruddhi chesindi. electron-droying groupulatho (trifluoroethyl) phosphonetlanu upayoginchi, balamgaa vidadeese paristhithulatho (khds mariyu 18-crown-6 thf) daadaapu pratyaekamaina jedd-alkeen utpattini saadhinchavachchu.
electron-lopam gala phosphonatela vadakam oxphosphaten madhyavartula tolagimpunu vegavantam chestundani aando suuchimchimdi.

