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Unformatted text preview: a) (1 S , 2 R ) and (1 R , 2 S ) b) (1 S , 2 R ) and (1 R , 2 R ) c) (1 S , 2 R ) and (1 S , 2 S ) d) (1 S , 2 S ) and (1 R , 2 R ) Comments: This question tests stereochemistry of reaction with know mechanism. There are several question of this type in the practice set, and one 14 on PE4C is almost identical. Other examples include: TS4: 30, 38, PE4A: 17, PE4B: 27, PE4C 7, 14. Br t-BuOK t-BuOH BH 3 /THF H 2 O 2 /NaOH D H H D H HO H H D 1R, 2S + mirror image Elimination has to be antiperiplanar, giving E alkene which adds HOH syn (through hydroboration). The addition can take place from either face of the double bond, giving the two enantiomers (one shown)....
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- Fall '07