Synthesis of Gelsemine

Structure of Gelsemine

C20H22N2O2

Principal investigator	Larry E. Overman
Publication year	2005
Synthesis type	Total
Number of steps	30 (linear)
References	J. Am. Chem. Soc. 2005, 127, 18046. J. Am. Chem. Soc. 2005, 127, 18054.

Part 1 of 1

intermediate structure

AlCl3, Methyl acrylate

CH2Cl2

-78 °C, 7 h, 98%

See the Diels-Alder Reaction

intermediate structure

SeO2

Dioxane

Reflux, 20 h, 90%

intermediate structure

Ph3P+CH3 Br-, n-BuLi

THF

-78 °C to RT, 3.5 h, 95%

See the Wittig Reaction

intermediate structure

KOH

EtOH, H2O

Reflux, 6 h, 91%

intermediate structure

(4-MeOPh)CH2OH, (PhO)2P(O)N3

Et3N, PhMe

Reflux, 12 h, 72%

See the Curtius Rearrangement

intermediate structure

PhOMe, CF3CO2H

CH2Cl2

RT, 90 min

intermediate structure

KCN, CH2O

THF, Buffer (pH = 7)

RT, 24 h, 81% (2 steps)

intermediate structure

n-Bu4N+ F-

THF

-30 °C to RT, 4 h, 95%

intermediate structure

KH , 18-Crown-6
2,6-Di-tert-butyl-4-methylpyridine , ClCO2Me

THF

-78 °C to RT, 2.5 h, 81%

See the Cope Rearrangement

intermediate structure

Pentamethylpyridine, Br2

CH2Cl2

-78 °C, 30 min

intermediate structure

(CF3CO)2O

CF3CO2H

Reflux, 14 h, 67% (2 steps)

See the Mannich Reaction

intermediate structure

TMS2NK
TESCl

THF

-78 °C to RT, 60 min

intermediate structure

PhIO, BF3.OEt2

CH2Cl2, MeOH

-78 to 0 °C, 3.5 h

intermediate structure

TMS2NK
Comins' reagent

THF

-78 °C, 30 min, 61% (3 steps)

intermediate structure

(dppf)PdCl2, CO, n-Bu3N

3.5 atm

DMF, MeOH

80 °C, 18 h, 94%

intermediate structure

o-Iodoaniline, AlMe3

CH2Cl2

-10 °C to RT, 3.5 h, 81%

intermediate structure

NaH
MeOCH2Cl

THF

RT, 12 h, 86%

intermediate structure

Ag3PO4, Pd2(dba)3.CHCl3, Et3N

THF

66 °C, 13 h, 70%

See the Mizoroki-Heck Reaction

intermediate structure

HCl

H2O, MeOH

RT, 48 h, 98%

intermediate structure

i-Bu3Al

PhMe

-50 °C to RT, 5 h, 71%

"Also isolated was the C3-epimer (12 % yield)."

intermediate structure

VinylOEt, Pyr.TsOH

CH2Cl2

RT, 90 min, 85%

intermediate structure

NaCN

DMSO

150 °C, 18 h, 99%

intermediate structure

MeOTf

CH2Cl2

0 °C, 15 min

intermediate structure

NaCN

DMSO

90 °C, 3 h, 85% (2 steps)

intermediate structure

TsOH

CH2Cl2, MeOH

90 °C, 60 min, 99%

intermediate structure

DBU

PhMe

110 °C, 9 h, 80%

intermediate structure

HCl

DME, H2O

55 °C, 3.5 h

intermediate structure

i-Pr2NEt

MeOH

55 °C, 20 h, 90% (2 steps)

intermediate structure

i-Bu2AlH

PhMe

0 °C to RT, 3 h

intermediate structure

Et3SiH, CF3CO2H

CH2Cl2

45 °C, 15 h, 65% (2 steps)

intermediate structure

Report an error in this part