Question

YUUKELUU W KTV GULVVVVVALU U U UPUPULU. TUU oxaphosphetane is not isolated but instead spontaneously decomposes to release triphenylphosphin and an alkene. The ylide is formed by reaction of triphenylphosphine, a good nucleophile, with a primary alkyl hal an Sp2 reaction, followed by deprotonation of the carbon with a strong base, such as butyllithium. 1 carbonyl carbon and the carbon originally bonded to the halogen become the two carbons with the d bond in the product alkene The real value of the Wittig reaction lies in its ability to yield an alkene of predictable structure, as th C-C bond is precisely where the O-O bond was in the reactant and no isomers (other than E/Z isome are formed. Draw curved arrows to show the movement of electrons in this step of the mechanism. Arrow-pushing Instructions Br-CH2CH3:PPh – Ph -CH2CH3 Bri ubmit Answer Retry Entire Group more group attempts remaining ant

Answer 1

Solution & klittig Reaction. снен, В. PP, Pй - сне с до Mechanismi CH3 - CH2 - Br + pphz + PPh 3 Steps CH3 - CH2 - PPh 3 Br NaH THE CH3 - CH - PPha + eta H2 t t Nabr - Step-3 step-2 6 yelide Ppha Он - сиз Step. z let cha CH - step. 3 CH₂ step- Betaine -ppha R CH - CH3 Oxaphosphetane CH-CH2 + P 3 step-5 Triphenyl alkene Phosphine oxide Step 1: Nucleophilic celtack of tripheral phosphine out on bromo ethane to form Wittig salto slep. 2: Reaction of klittig satt salt with Nahin THE to form yelide. Step 3: Reaction of Telide with caldehyde or ketone to form Betaine Step 4: Betaine under ques cyclisation to form oxaphosphetane ring. step-s: Oxaphosphet une ring eliminate triphenyl Phosphine oxide to give alkene.