Reduction of a,- unsaturated carbonyl compounds Edited by Chen Peng, Gao Dong
Reduction of a,b - unsaturated carbonyl compounds Edited by Chen Peng , Gao Dong
Part one Chemoselective Reductions or not?
Part one Chemoselective Reductions or not?[1]
By Nabh4 or LiAlH4 A is obtained orb ??? O OH HO C=c—C C=c—C +H—C—C—C H H B
By NaBH4 or LiAlH4 A is obtained or B ??? C C C O C C C O H H C C C HO H H H + A B
Substrate Yield.NaBHa, 50% aqueous EtoH- LiAlH, ether- %o A 7 B Yield, %o 7A %O B CH,-CHCCH( CHCH=CHOCH,(2) 65 35 98 (CHA)C=CHOCH(3) 92 59 97 100 CH, "CHCH (6) CHCHe CHCH (7) 92 94 100 CH=C-cH⑧ ≥99 ≤1 98 ≥99 ≤1 CHO
Other way to illustrate CH3 O (CH3)2C-CHCCH3 2HC-C-CH2 CHCH2 OH OH C OH (CH3)2C-CHCHCH2 (CH3)2CHCHCHCH2 H2C=CCH2 CHCH2 22 23 Starting - meteria 一 Product distribution %6 3 21 Reduction conditions %o12 22 %23 97 3 LiAlH, ether 60 40 LiAIH, ether 040 97 3 NaBH4, 50%o aq ethanol 97 3 NaBH, 507 aq methanol 87 10 3 60 40 NABH, i-PrOH 561725 97 3 NaBH, i-PrOH 542817
H2C C CH3 CH2CHCH2 OH CHCH2 OH (CH3)2C CH CHCH2 OH (CH3)2CHCH2 + + CHCCH3 O (CH3)2C 2HC C CH3 CH2CHCH2 O + 3 21 12 22 23 Other way to illustrate