Protecting group
Acetal
Stable to base, nucleophiles, reducing agents. Removed by acid.
Octet · Reference tables
Look it up in seconds, not chapters.
Look up pKa, IR, H NMR, C NMR, and protecting-group reference records.
- 109 records here
- 5 tables: pKa, IR, ¹H, ¹³C, protecting groups
83Reactions
63Reagents
25Groups
109Reference rows
0Saved
0%Quiz accuracy
pKa
Acetic acid (CH₃COOH)
pKa 4.76
4.76
pKa
Acetone (α-H)
Enolizable
20
pKa
Acetonitrile (α-H)
pKa 25
25
Protecting group
Acetyl
Forms ester (for OH) or amide (for NH₂). Removed by base hydrolysis.
pKa
Acetylene (≡C-H)
Terminal alkyne
25
IR
Acyl halide C=O
Absorbs at 1795-1815 cm⁻¹
1795-1815
IR
Alcohol O-H
Absorbs at 3200-3600 cm⁻¹
3200-3600
H NMR
Aldehyde (R-CHO)
¹H shift 9.5-10.0 ppm
9.5-10.0
IR
Aldehyde C-H
Absorbs at 2700-2850 cm⁻¹
2700-2850
IR
Aldehyde C=O
Absorbs at 1720-1740 cm⁻¹
1720-1740
pKa
Alkane (C-H)
Essentially non-acidic
~50
IR
Alkane C-H (sp³)
Absorbs at 2850-3000 cm⁻¹
2850-3000
pKa
Alkene (=CH)
~44
IR
Alkene =C-H (sp²)
Absorbs at 3000-3100 cm⁻¹
3000-3100
IR
Alkene C=C
Absorbs at 1620-1680 cm⁻¹
1620-1680
IR
Alkyne ≡C-H (sp)
Absorbs at 3300 cm⁻¹
3300
IR
Alkyne C≡C
Absorbs at 2100-2260 cm⁻¹
2100-2260
H NMR
Allylic (C=C-CH)
¹H shift 1.6-2.0 ppm
1.6-2.0
IR
Amide C=O
Absorbs at 1630-1690 cm⁻¹
1630-1690
IR
Amide N-H
Absorbs at 3150-3400 cm⁻¹
3150-3400
H NMR
Amide N-H
¹H shift 5-8 ppm
5-8
IR
Anhydride C=O
Absorbs at 1740-1840 cm⁻¹
1740-1840
H NMR
Ar-OH (phenol)
¹H shift 4-8 ppm
4-8
C NMR
Aromatic C (general)
¹³C shift 110-160 ppm
110-160
C NMR
Aromatic C-C (ipso)
¹³C shift 125-150 ppm
125-150
IR
Aromatic C-H
Absorbs at 3000-3100 cm⁻¹
3000-3100
C NMR
Aromatic C-H
¹³C shift 110-130 ppm
110-130
C NMR
Aromatic C-O
¹³C shift 150-165 ppm
150-165
IR
Aromatic C=C
Absorbs at 1450-1600 cm⁻¹
1450-1600
H NMR
Benzene ring
¹H shift 6.5-8.5 ppm
6.5-8.5
pKa
Benzoic acid
pKa 4.2
4.2
Protecting group
Benzyl
Stable to base and mild acid. Removed under hydrogenation.
H NMR
Benzylic (Ar-CH)
¹H shift 2.2-2.5 ppm
2.2-2.5
C NMR
C-N (amine)
¹³C shift 30-65 ppm
30-65
C NMR
C-O (alcohol, ether)
¹³C shift 50-90 ppm
50-90
IR
C-O (alcohols, ethers)
Absorbs at 1050-1150 cm⁻¹
1050-1150
IR
C-O (esters)
Absorbs at 1000-1300 cm⁻¹
1000-1300
C NMR
C-X (halide)
¹³C shift 10-75 ppm
10-75
C NMR
C=C (alkene)
¹³C shift 100-150 ppm
100-150
C NMR
C=O (aldehyde)
¹³C shift 190-205 ppm
190-205
C NMR
C=O (amide)
¹³C shift 160-180 ppm
160-180
C NMR
C=O (carboxylic acid)
¹³C shift 170-185 ppm
170-185
C NMR
C=O (ester)
¹³C shift 160-175 ppm
160-175
C NMR
C=O (ketone)
¹³C shift 195-220 ppm
195-220
C NMR
C≡C (alkyne)
¹³C shift 65-90 ppm
65-90
C NMR
C≡N (nitrile)
¹³C shift 115-125 ppm
115-125
H NMR
Carboxylic acid (R-COOH)
¹H shift 10-12 ppm
10-12
IR
Carboxylic acid C=O
Absorbs at 1700-1725 cm⁻¹
1700-1725
IR
Carboxylic acid O-H
Absorbs at 2500-3300 cm⁻¹
2500-3300
IR
Conjugated C=O
Absorbs at 1665-1685 cm⁻¹
1665-1685
H NMR
Electron-poor aromatic
¹H shift 7.5-8.5 ppm
7.5-8.5
H NMR
Electron-rich aromatic
¹H shift 6.5-7.5 ppm
6.5-7.5
IR
Ester C=O
Absorbs at 1735-1750 cm⁻¹
1735-1750
pKa
Ethanol
pKa 16
16
pKa
Ethyl acetate (α-H)
Ester enolate
25
Protecting group
Fluorenylmethyloxycarbonyl
Removed by base (not acid). Orthogonal to Boc. Standard in solid-phase peptide synthesis.
pKa
H₂ (dihydrogen)
pKa 35
35
pKa
H₂CO₃
Carbonic acid
6.4
pKa
H₂O
OH⁻
15.7
49 records still below