Question

3. Draw structures of the compounds A and B and indicate relative configuration of the stereocenters (where applicable) using wedges and dashes. OH N1 A 1. X 2. H30* 1. OsO4 2. NaHSO, - в HBr A (CH3CH2)2COK (CH3CH2),COH B CHCE N°49 ano C2H5= Na/NH3 () A pesan, C2H5 — -33°C d. CH2Cl2, 20°C

Answer 1

HO CH₂ ROH ОН ŘSH 1. Os04 2. NaHSO, HOJE HO CH₂ 2. H20* SOH ROH SYUR mCPBA gives epoxide and it is hydrolysed in acid to give transdiol mixture of enantiomers. Osmenium tetraoxide reacts with dioll to give cis diol. Another pair of enantiomers. HBr, CH3 WCH [ Brº (CH3CH2jąco®k® b. (CH2CH2)2COH 1-bromo-1-methylcyclohexane methylidenecyclohexane Br CH3 " c. Hic-= H26-=c? - =c. <H3c H3C- hex-2-yne

ch, = C,H, Na, N, P Ro Na/NH3 ( H5C? ih -33°CH C,H, CHCl, 20°C (3E)-hex-3-ene H5C20H HCM : Ã CHE (2S,3S)-2,3-diethyloxirane