Jung Michael E Im GYoon J Convergent total

Luche Reduction Ce. Cl 3 promotes the 1, 2 reduction of a, b-unsaturated ketones,

Piv. Cl = pivaloyl chloride = t-Bu-COCl TBS-Cl = tert-Butyldimethylsilyl Chloride DIBAL = Diisobutylaluminum

Ley, Steven V. ; Norman, Joanne; Griffith, William P. ; Marsden, Stephen P. Tetrapropylammonium

Li. HMDS = Lithium Hexamethyldisilazide = Li. N(Si. Me 3)2

Boukouvalas, John; Wang, Jian-Xin. Structure Revision and Synthesis of a Novel Labdane Diterpenoid from

LAB = Lithium amidotrihydroborate = Li. H 2 NBH 3

TIPS = Triisopropylsilyl PCC = Pyridinium Chlorochromate

TFEF = 2, 2, 2 -trifluoroethyl formate = HCO 2 CH 2 CF 3

Donohoe, Timothy J. ; Thomas, Rhian E. ; Cheeseman, Matthew D. ; Rigby, Caroline

Li. TMP = Lithium tetramethylpiperidide DBB = Di-tert-butylbiphenyl Boc = tert-butyloxycarbonyl = t-Bu. O-CO

However, the original Birch reduction conditions have some drawbacks, one of which is the

Red-Al is less oxygen sensitive and more soluble than Li. Al. H 4.

TMO = trimethylamine-N-oxide p. TSA = p-toluenesulfonic acid

Li. BH 4 is a somewhat stronger reducing agent than Na. BH 4 …

Slides: 63

Download presentation

Jung, Michael E. ; Im, G-Yoon J. Convergent total synthesis of the racemic HIF-1 inhibitor laurenditerpenol. Tetrahedron Letters (2008), 49(33), 4962 -4964.

Luche Reduction Ce. Cl 3 promotes the 1, 2 reduction of a, b-unsaturated ketones, over the conjugate (1, 4) reduction. Link

DIBAL = Diisobutylaluminum Hydride Link

Piv. Cl = pivaloyl chloride = t-Bu-COCl TBS-Cl = tert-Butyldimethylsilyl Chloride DIBAL = Diisobutylaluminum Hydride TPAP = Tetrapropylammonium Perruthenate NMO = N-Methylmorpholine-N-oxide

Ley, Steven V. ; Norman, Joanne; Griffith, William P. ; Marsden, Stephen P. Tetrapropylammonium perruthenate, Pr 4 N+Ru. O 4 -, TPAP: a catalytic oxidant for organic synthesis. Synthesis (1994), (7), 639 -66.

Li. HMDS = Lithium Hexamethyldisilazide = Li. N(Si. Me 3)2

Julia Olefination Link

Diimide Reductions

Boukouvalas, John; Wang, Jian-Xin. Structure Revision and Synthesis of a Novel Labdane Diterpenoid from Zingiber ottensii. Organic Letters (2008), 10(16), 3397 -3399.

Weinreb Amide

Weinreb Amide General

LAB = Lithium amidotrihydroborate = Li. H 2 NBH 3

TIPS = Triisopropylsilyl PCC = Pyridinium Chlorochromate

TFEF = 2, 2, 2 -trifluoroethyl formate = HCO 2 CH 2 CF 3

Donohoe, Timothy J. ; Thomas, Rhian E. ; Cheeseman, Matthew D. ; Rigby, Caroline L. ; Bhalay, Gurdip; Linney, Ian D. Flexible Strategy for the Synthesis of Pyrrolizidine Alkaloids. Organic Letters (2008), 10(16), 3615 -3618.

Li. TMP = Lithium tetramethylpiperidide DBB = Di-tert-butylbiphenyl Boc = tert-butyloxycarbonyl = t-Bu. O-CO

Birch Reduction

Mechanism of the Birch Reduction

However, the original Birch reduction conditions have some drawbacks, one of which is the use of liquid ammonia as solvent. The use of other electron donating reagents can permit the use of THF as solvent.