
hydrasone iodenation

iodine, dbu polulla nucleophilic ithara shaarangal ennivayude prathikaranatthiloode oru hydrasone vinail iodide parivartthanam cheiyunna oru jaiva prathikaranamaanu hydrasone iodenation. 1962 ll derek barton aadyamaayi prasidheekaricha eee prathikaranatthe chilappol barton prathikaranam (niravadhi vyathyastha barton prathikaranangal undengilum) allengil kooduthal vivaranaathmakamaayi, barton vinail iodine nadapadikramam ennu vilikkunnu.
1911ll wyland rosyuvum kandethiya hydrasonukalude ayodinumaayulla prathikaranam (aditharayillaathe) assain diamerinu ("skeem 1" leeii ghadana 2) kaaranamaakunnu.
yadhaartha barton prasidheekaranathil sakthamaaya gwanidin bays upayogichum iodine laayaniyilekk hydrasone vipareethamaayi chertthum vellam ozhivaakkiyum prathikaranam opttimais cheythu.
oru electrophyl enna nilayil iodine sugandha selenyl bromideukalaal maattisthaapikkappedum, anubandha vinail selenideukal labikkum
prathikarana samvidaanam.
yadhaartha barton prasidheekaranathil nirddeshichittulla prathikarana samvidaanam inipparayunna reethiyil vivarichirikkunnu
hydrasone iodine upayogichu oru diazo intermediattaayi ooksidais cheyyappedunnu. adutha ghattathil, iodine oru electrophyl aayi prathipravartthikkunnu; naitrajante sthaanachalanathiloode oru iodocarbon ayoon srishtikkunnu. prathikarana saitt sterikkaayi thadassappedaathappol, randaamathe iodide veendum samyojippichu jaeminal dye-iodide roopappeduthaan kazhiyum; allengil oru elemination prathikaranam vineliodidelake nayikkunnu. vellam undaakumbol, prathikarana uthppannathin kettonilekku madangaan kazhiyum. 
eee prathikaranam shapiro prathikaranavumayi bandhappettirikkunnu.
vyaapthi.
reflexil ethanolile hydrassin, triathilaamain ennivayumaayulla prathikaranatthiloode hydrasoninode 2,2,6-trimethylsaikloheksano nadathunna prathikaranavum thudarnnu room thapanilayil diethyl eetharile 2-tert-beautil-1,1,3,3-tetramethylguanidine (dbu-nekkaal vilakuranja) ennivayude saannidhyathil ayodinumaayi hydrasone nadathunna prathikaranavumaanu eee prakriyayude oru udaaharanam. mattoru udaaharanam danishefsky taxol total synthesisil kaanam. 
oru padanatthil eee prathikaranatthinte eathenkilum prathipravartthana idatharam oru aantharika alkeen upayogichu kettaan shramikkunnu. skeem 5" leeii hydrasone 1, tollunile iodine, triathilaamain ennivayumaayi prathipravartthikkumbol, prathekshikkunna prathikarana uthppannam oru free radical samvidaanathile dye-iodide 10 muthal paathu bii vare allah. 1 muthal aarambikkunna prathikarana kramam dye-iodide intermediat 2 lekkulla halojan kootticherkkal prathikaranam, hydrajan iodide 3 lake nashtappedunnathinoppam elemination prathikaranam. bii pathayil iodine thulyamaaya mattoru prathikaranam asso erattabandhathodum thudarnnu hye nashtappedukayum 6 roopappedukayum cheiyunnu. naitrajan iodine bondilekku durbalamaavukayum homolysis naitrajan free radical nalkukayum cheiyunnu. naitrajan nashtappedunnathu radical speesheesilekku nayikkunnu. 8. radical sthaanam 9-ll aalkkeenilekk maarunnu, athu pinneedu iodidemaayi 10 lake veendum samyojippikkunnu. alkeen 8-nte abhaavathil oru iodide radical jaeminal dye-iodide nashtappedukayum vinail iodide roopappedukayum cheiyunnu. diazo samyuktham 4 lake hye neekkam cheiyunnathinoppam 85 sathamaanam vilavil pyrasoline 5 lake diasoalkeyn 1,3-dipolar cycloload cheiyunnathiloodeyaanu yadhaartha prakriya nadakkunnathu.

