Question

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3. Draw the major product of the final step of the following scheme in the box provided. 1. NBS, ROOR or NBS, cat AIBN, CCls, heat 2. DBN 3. Hydroboration-oxidation 4. PBr3 5. Mg, Et2o 6. PhCHO, then workup 7. Jones reagent 8. PhLi, Et O, then H30 9. TsOH, heat 10. NBS, HOH 11. NaOH (intramolecular SN2) 12. MeMgBr (excess), then workup 13. E2 14. HBr 15. Mg, ether 16. dry ice, then workup 17. LiAlH4, ether, then workup 18. SOCI2, pyridine 19. CH3COO Na, aprotic solvent 20. LiAlH4, THF, then workup mqjorproduct (ignore stereochemistry) 4. In less than 7 steps, show how alcohol X may be conveniently prepared from cyclohexanone. Ph more than one step Ph Me

Answer 1

13s Ai ccI , heat Position Bom, nakon Base) [ Base elimination〕 [allylic l Base elieiration BH 3bozidolion A. PB63 2 alcohel aeacsith LHudzobosation followed bay ozidation 3 gives ng H202 gives alcohol ] omide insestron of Ma to , C-X bond] rigBo·6" a.Pn_C_. I.) G. buoosh up Ph 04 riucleophtle attack at aldehyde -alcohel ozidation of alcohol to etone 7.Jones eagen [Healing wsth iclephilkc afloch ot helonic Heating with Bols, give s alhene Nuc leophilic aftac casbon

Ph Ph ion and attach fsom move substitute 112 O ph side ) Ph OH L Base abstaacto the nnd -o-attacks on neighbơ Ph Ph axabon to form epoxide Nucleoph:lic attack a 72, Me MgBs Cexcess least substsheted Caabonコ Ph [탰 elimination leads to alhene 13. Ep, Ph rnddition of HST gives alky I baomde 4. 483 Tascation of Mg to C- Bos bond Mgethes Ph Bs nNucleophile attachs at Co ic. day ice」,hen wosk sup

wosh up Rudruction of CooH gp to 19. 30Cly, Pyoi inte alhyl halrd Ph Ph ㄚ一@g < aprotic soんent n wosh up lauduction of Ph esteづ gives alcohol OH OH -t LDA Ph Cw,- I 1.2:, H. THF O4 Ph wosk ap cyclohezanone veacts with IDA & G methyl cyclohe ranone is fosme ︵ fuathexandegoes wito eact on, hydrogenction and eaction with