Question

6. Provide the mechanisms for the following reactons MgBr 1. Excess OH OCH 2. H30 som HB HBr 1. LIAIH4 O2. H30+ 7. Suggest a structure for an unknown A whose formula is CH160 and gives the following chemical test results. Formula C6H100 Hydrogenation Test H/Pt Chromic Acid Test HaCrO4 Lucas Test HCI/ZnCl2 • Reacts to give C H20 Reacts, turns green/brown, precipitate for Reacts, a new oil layer forms on top.

Answer 1

GIL focus Bongo OCPZ + I nger OH First the frignard reagent reat with the tester to form. a ketone and then the present excess Gooign and reagent again attack the ketone to form a secondary alhot after protonation.

O stable ze combocation В. First the giren tertiary alchol condergo rapid protonation and then forma stable to carbocation. The present Br then attack the carbocation to form tertiary bromide by SNL mechanism. 1. LiAlH4 LAIHA , Coupon 2. Hot - Olim a r On. AU Here the LiAlta transfer one to to the Carberry1 corben by the oxelic mechanism so ho selectively attack on only the corboryl Corben. Aber After protonation weget the following product.

the given compound recats with Hop/pt and after reacting the number of A increase by 2 r.e. CCHIO CCAIRO so 'c=é must be present. the given compound reacts with Chromic acid and tros green precipitate, so here to log ² (green) So, the compound must excidhe reduction on on Lucas test q. e. with Hel/ench the compound torms oll layer on top. so, It must be an sesan dan akhol.either secondry or tertiory. But Chromic and con oscilise only secondry alchoto So, the compound must be a secondry alahas. So, it could be, CH=CH CH=CH-CH-Clz i.e. E 애 Ni From double bond equirelent calculation no. of double bend = noote- no.077 +1 2 - 6-10 = lt1 -2 the comporma could be Cl22=CH-CH=CH - CH-CH3 OH 9A CH₂=CH-CH=CH-eh-em & H2 ) Caz- eA-CH=CH-CH -ca (12=CH-CH=CH-CA-CH3 Beson 애 eh Cl2 = CH – CH-CH 2 Hl. nel cas