Indium-mediated cleavage of the trityl group from protected alcohols and diols

Article abstract of DOI:10.1016/j.tet.2016.10.020

The reaction of primary, secondary, allylic and benzylic trityl ethers with indium powder in MeOH/NH₄Cl led to reductive cleavage of the trityl-oxygen bond, affording the corresponding alcohols in good to excellent yield under very mild reaction conditions. The detritylation process could successfully be extended to mono and detritylated diols. This methodology represents a new and efficient detritylation procedure under mild reaction conditions.

Full text of DOI:10.1016/j.tet.2016.10.020

Accepted Manuscript
Indium-mediated cleavage of the trityl group from protected alcohols and diols
Cherif Behloul, Aicha Chouti, David Guijarro, Francisco Foubelo, Carmen Nájera,
Miguel Yus
PII:
S0040-4020(16)31042-0
10.1016/j.tet.2016.10.020
TET 28161
DOI:
Reference:
To appear in: Tetrahedron
Received Date: 9 July 2016
Revised Date: 26 September 2016
Accepted Date: 10 October 2016
Please cite this article as: Behloul C, Chouti A, Guijarro D, Foubelo F, Nájera C, Yus M, Indium-
mediated cleavage of the trityl group from protected alcohols and diols, Tetrahedron (2016), doi:
10.1016/j.tet.2016.10.020.
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ACCEPTED MANUSCRIPT
Indium-mediated cleavage of the trityl group from
protected alcohols and diols
Cherif Behloul,*a Aicha Chouti,a David Guijarro,b,c Francisco Foubelo,b,c,d Carmen Nájera,b,d
Miguel Yusb,d
a
Laboratoire des Produits Naturels d’Origine Végétale et de Synthèse Organique, Université des Frères Mentouri-
Constantine 25000 (Algérie)
b Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Alicante, Apdo. 99, 03080 Alicante (Spain)
c Instituto de Síntesis Orgánica (ISO), Universidad de Alicante, Apdo. 99, 03080 Alicante (Spain)
d
Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Alicante, Apdo. 99, 03080 Alicante
(Spain)
Tel/Fax: 213 31 81 88 62
Email: afiza72@gmail.com
Received: The date will be inserted once the manuscript is accepted.
Dedicated to Professor José Elguero on occasion of his 80th birthday
Keywords: indium, detritylation, trityl ethers, protected alcohols, protected diols
Abstract: The reaction of primary, secondary, allylic and benzylic trityl ethers with indium powder in MeOH/NH4Cl led to reductive
cleavage of the trityl-oxygen bond, affording the corresponding alcohols in good to excellent yield under very mild reaction conditions.
The detritylation process could successfully be extended to mono and detritylated diols. This methodology represents a new and
efficient detritylation procedure under mild reaction conditions.
1. Introduction
The use of indium metal1 in reduction processes applied to synthetic organic chemistry2 is
based on the fact that its electrode potential (5.8 eV) is rather similar to that of alkali metals, such as
sodium (5.1 eV) or lithium (5.4 eV) and, therefore, indium metal behaves as an excellent single
electron transfer reagent.3 This ability has been used successfully for the cleavage of carbon-
heteroatom bonds and, consequently, for the deprotection of several functionalities such as protected
alcohols, amines or thioethers.4 Among interesting protecting groups, the triphenylmethyl (trityl) unit
has been extensively used in carbohydrate,5 peptide,6 and nucleoside chemistry,7 mainly due to its
steric demand. In addition, deprotection of the trityl group can be easily achieved by simple acid
hydrolysis,4 this procedure being useful only for compounds having functionalities not-sensitive to
acidic conditions: as an example when nucleosides are tritylated at the 5’-OH position, its treatment
with protic acids leads, together with the expected detritylation, to the hydrolysis of the N-glycosidic
bond.8
In the last years, we have been interested in the deprotection of several oxygen, nitrogen and
sulfur-containing compounds9 using lithium and a catalytic amount of naphthalene10 followed by
hydrolysis. Among them, we investigated detritylation processes involving trityl ethers9a and trityl
amines.9g In addition, more recently, we have explored the use of other metals, such as indium11 or
zinc,12 in both cases in methanol, for the effective detritylation of 1-trityltetrazoles.13,14 In this paper,

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we report the indium-promoted detritylation of trityl ethers as an efficient method for the
deprotection of this type of compounds under very mild reaction conditions.
2. Results and discussion
As a model reaction we treated n-nonadecyl trityl ether (1a) with indium metal (1:1.7 molar
ratio) under different reaction conditions finding that the optimal situation was the use of a mixture of
methanol and aqueous ammonium chloride at reflux for 35 hours (Table 1, entry 8). Using other
solvent combinations or diminishing the reaction temperature or time, no reaction occurred (Table 1,
entries 1-7).
Table 1
Assayed conditions for the In-promoted
cleavage of 1a for 24 h
_____________________________________
EntrySolvent
T (ºC)
Yield (%)a
_____________________________________
1
2
3
4
5
6
7
In/MeOH/THF
In/MeOH/THF
In/MeOH
rt
0
0
0
0
0
0
reflux
rt
In/MeOH
reflux
rt
In/THF
In/THF
reflux
In/MeOH/THF/
NH4Cl
rt
0
8
In/MeOH/NH4Cl
refluxb 80
______________________________________
b
2Isolated yield. For 35 h.
Having the best reaction conditions in hand, we studied the scope of the process. Primary (1a-
d, Table 2, entries 1-4) or secondary (1e-g, Table 2, entries 5-7) trityl ethers were easily deprotected
to afford the expected alcohols 2a-g with yields ranging from 62 to 80%. Mono (1h, Table 2, entry 8)
and ditritylated diols (1i,j, Table 2, entries 9 and 10) were fully deprotected using the same reaction
conditions with the corresponding stoichiometry, affording the expected diols 2h-j. The low yield
obtained for diols 2h-j could be explained by their partial solubility in water during the extractive
work-up; actually no byproducts were observed in the reaction crude. Also allylic or benzylic
derivatives (1k and 1l, respectively, Table 2, entries 11 and 12) were detritylated without any

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problem: allylic or benzylic carbon-oxygen cleavage was not observed in any case. Finally, the
protected phenol 1m (Table 2, entry 13) was submitted to the same protocol giving the parent phenol
with reasonable yield.
Table 2
Indium-mediated detritylation of ethers 1
Entry
1
Substrate
t (h)
35
Product Yield (%) a
80
2
3
30
28
70
71
OH
2d
4
5
30
62
32
68
75
6
31
7
8
31
28
70
56
9
34
60

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10
11
30
58
62
30
12
27
81
13
25
68
a Yield of isolated product after purification by column chromatography (hexane/ethyl acetate), based on the starting
material 1.
Starting ethers 1 were easily prepared from the corresponding commercially available
alcohols 2 by a standard procedure: reaction of 2 with trityl chloride in the presence of triethylamine
and a catalytic amount of 4-dimethylaminopyridine.9a
Concerning a possible reaction mechanism, we believe that after the first single electron
transfer (SET) from the metal to the ether, a trityl radical is formed, which after a second SET
process gives the corresponding anion that in the reaction medium captures a chloride from
ammonium chloride, giving trityl chloride. The alkoxide formed in the first step also traps a proton
from the protic reaction medium to give the alcohol 2. Actually, in order to support this proposal we
were able to isolate trityl chloride (65%; column chromatography, silica gel hexane-EtOAc 9:1) in
the detritylation of 1a under the conditions shown in Table 2.
As a conclusion, we have reported here a simple, versatile and useful methodology for the
detritylation of protected primary and secondary alcohols, as well as mono- or diprotected diols, and
tritylated phenol, using indium in a protic medium.
3. Experimental part
3.1. General
FT-IR spectra were recorded on a Nicolet Impact 400D spectrophotometer and Fourier Shimadzu
FTIR-8201 PC using KBr pellets. NMR spectra were recorded on a Bruker AC-300 spectrometer (300 MHz
for 1H and 75 MHz for 13C) and a Bruker AC-400 spectrometer (400 MHz for 1H and 100 MHz for 13C) using
CDCl3, DMSO-d6, or CD3OD as solvent and TMS (δ = 0.00 ppm, 1H) or CDCl3 (δ = 77.0 ppm, 13C), DMSO-
d6 (δ = 2.50 ppm, 1H; δ = 39.75 ppm, 13C), or CD3OD (δ = 4.87 ppm, 1H; δ = 49.0 ppm, 13C), Fourier

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BRUCKER DPX 250 (250 MHz for 1H and 62.5 MHz for 13C) as internal standards; chemical shifts are
given in δ (ppm) and coupling constants (J) in Hz. Multiplicities are given as s: singlet, d: doublet, t: triplet, td:
triplet of doublet, m: multiplet. Elemental analyses were measured by the Technical Services at the University
of Alicante. Column chromatography was performed using silica gel 60 (35-70 mesh). All reagents used for
the synthesis of trityl ethers were of the best commercial grade and were uses as received.
3.2. General procedure for tritylation of alcohols 2. Preparation of ethers 19a,13
A solution of the commercially available alcohol 2 (5.0 mmol) in CH2Cl2 (2.5 mL) was
added to a solution of trityl chloride (1.55 g, 5.5 mmol), Et3N (1.25 mL, 8.8 mmol) and DMPA (46
mg, 0.2 mmol) in CH2Cl2 (5 mL) at rt and the mixture was stirred overnight. The reaction was then
quenched with water (2.5 mL) and extracted with EtOAc (3 × 10 mL) and the combined organic
phases were washed with brine (2.5 mL) and dried over sodium sulfate. After evaporation of the
solvents (15 Torr), the resulting residue was purified by column chromatography (silica gel, hexane-
EtOAc) affording the expected trityl ethers 1. When diols were used (as precursor of ethers 1h-j), a
mixture of mono and deprotected products were obtained in variable proportions, which could be
easily separated by column chromatography. Physical, spectroscopic and analytical data for the
tritylated alcohols 1 follow.
3.2.1. Stearyl trityl ether (1a).13 White solid; yield 2.45 g (95%); mp: 70 °C; IR (cm-1): 3000, 2950,
2400, 1500, 1450, 1300, 1050, 1010, 650; 1H NMR (400 MHz, CDCl3): δ 0.81 (t, 3 H, J = 4.0 Hz,
CH3), 1.18–1.56 [m, 24H, CH3(CH2)12], 2.20–2.22 (m, 6H, 3 CH2), 2.49-2.52 (m, 2H, CH2CO), 2.96
(t, 2H, J = 6.7 Hz, CH2O), 7.13–7.25 (m, 9H, ArH), 7.36–7.38 (m, 6H, ArH); 13C NMR (100 MHz,
CDCl3): δ 14.1 (CH3), 22.6, 26.2, 29.3, 29.6 (8C), 30.0, 31.9, 39.9, 40.1, 40.3 [CH3(CH2)16], 63.6
(CH2O), 86.5 (CO), 126.7 (3C), 127.6 (6C), 128.6 (6C), 144.5 (3C, ArC); MS m/z (%): 435 (M+-Ph,
8), 244 (39), 243 (100), 183 (29), 165 (15), 105 (16); Anal. Calcd for C37H52O: C, 86.66; H, 10.22.
Found: C, 86.62; H, 10.26.
3.2.2. Hexyl trityl ether (1b).13 Colorless oil; yield 1.18 g (62%); IR (cm-1): 3166, 3058, 3028, 1593,
1488, 1080, 1068; 1H NMR (250 MHz, CDCl3): δ 1.22 (d, 3H, J = 6.1 Hz, CH3), 1.53–1.81 [m, 6H,
CH3(CH2)3], 3.08–3.17 (m, 2H, CH2CH2O), 3.76–3.88 (m, 2H, CH2O), 7.23–7.37 (m, 9H, ArH),
7.42–7.50 (m, 6H, ArH); 13C NMR (62.5 MHz, CDCl3): δ 23.6 (CH3), 26.5, 36.4 (2C), 63.8
[CH3(CH2)4], 68.0 (CH2O), 86.7(CO), 127.0 (3C), 127.8 (6C), 128.7 (6C), 144.3 (3C, ArC); MS m/z
(%): 243 (M+-Ph-CH2=CH2, 100), 183 (30), 167 (11), 166 (7), 165 (21), 105 (31), 77 (20); Anal.
Calcd for C25H28O: C, 87.16; H, 8.19. Found: C, 87.18; H, 8.16.
3.2.3. n-Decyl trityl ether (1c).9a Colorless oil; yield 1.85 g (76%); IR (cm–1): 3085, 3057, 3031,
1596, 1489, 1086, 1068; 1H NMR (400 MHz, CDCl3): δ 0.87 (t, 3H, J = 8.0 Hz, CH3), 1.24–1.36 [m,
14H, CH3(CH2)7], 1.51–1.65 (m, 2H, CH2CO), 3.03 (t, 2H, J = 6.7 Hz, CH2O), 7.19–7.31 (m, 9H,
ArH), 7.43–7.46 (m, 6H, ArH); 13C NMR (100 MHz, CDCl3): δ 14.2 (CH3), 22.8, 26.4, 29.4, 29.6,
29.7 (2C), 30.2, 32.0 [CH3(CH2)8], 63.8 (CH2O), 86.3 (CO), 126.9 (3C), 127.8 (6C), 128.8 (6C),
144.6 (3C, ArC); MS m/z (%): 400 (M+, 12), 323 (16), 244 (36), 243 (100), 183 (35), 165 (39), 105
(40).

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3.2.4. Isoamyl trityl ether (1d).15 Colorless oil; yield 1.24 g (75%); IR (cm-1): 3070, 3024, 2912,
1485, 1446, 1083; 1H NMR (400 MHz, CDCl3): δ 0.80 (d, 6H, J = 8.0 Hz, [m, 1H, CH(CH3)2], 1.47–
1.53 (m, 2H, CH2CH2O), 1.72-1.79 [m, 1H, CH(CH3)2], 3.06 (t, 2H, J = 8.0 Hz, CH2O), 7.25–7.36
(m, 9H, ArH), 7.49–7.51 (m, 6H, ArH); 13C NMR (100 MHz, CDCl3): δ 22.8 (2CH3), 25.2 (CH),
39.1 (CH2), 68.2 (CH2O), 86.4 (CO), 126.9 (3C), 127.8 (6C), 128.8 (6C), 144.6 (3C, ArC); MS m/z
(%): 330 (M+, 10), 244 (32), 243 (100), 253 (11), 183 (33), 165 (32), 105 (25); Anal. Calcd for
C24H26O: C, 87.23; H, 7.93. Found: C, 87.25; H, 7.90.
3.2.5. 2-Trityloxyoctane (1e).9a Colorless oil; yield 1.60 g (78%); IR (cm-1): 3055, 2925, 1598, 1489 ,
1075, 1026; 1H NMR (400 MHz, CDCl3): δ 0.83 (t, 3H, J = 8.0 Hz, CH3CH2), 0.86 (d, 3H, J = 4.0
Hz, CH3CO), 1.05–1.23 [m, 10H, (CH2)5], 3.51–3.58 (m, 1H, CHO), 7.19–7.30 (m, 9H, ArH), 7.49–
7.52 (m, 6H, ArH); 13C NMR (100 MHz, CDCl3): δ 14.2 (CH3CH2), 21.3 (CH3CO), 22.7, 25.0, 29.5,
31.9, 37.6 [(CH2)5], 70.2 (CHO), 86.5 (CO), 126.8 (3C), 127.7 (6C), 129.1 (6C), 145.7 (3C, ArC);
MS m/z (%): 372 (M+, 4), 244 (30), 243 (100), 183 (39), 165 (48), 105 (43).
3.2.6.Cyclopentyl trityl ether (1f).13 White solid; yield 0.82 g (62%); mp 84 °C; IR (cm-1): 3055,
3028, 1596, 1485, 1045; 1H NMR (300 MHz, CDCl3): δ 1.18–1.35 [m, 6H, (CH2CHH)2], 1.50–1.64
[m, 2H, (CH2CHH)2], 3.95–4.07 (m, 1H, CHO), 7.15–7.31 (m, 9H, ArH), 7.45–7.53 (m, 6H, ArH);
13C NMR (75 MHz, CDCl3): δ 23.8, 33.7 [(CH2)4], 76.5 (CHO), 86.9 (CO), 126.8 (3C), 127.8 (6C),
129.0 (6C), 145.6 (3C, ArC); MS m/z (%): 251 (M+-Ph, 6), 244 (34), 243 (100), 183 (18), 166 (6),
165 (44), 105 (17); Anal. Calcd for C24H24O: C, 87.76; H, 7.37. Found: C, 87.73; H, 7.41.
3.2.7. Cyclohexyl trityl ether (1g).9a White solid; yield 1.58 g (92%); mp 85 °C; IR (cm-1): 3000,
3010, 1600, 1450, 1000; 1H NMR (400 MHz, CDCl3): δ 1.01–1.35 [m, 6H, (CH2)3], 1.52–1.61 (m,
4H, 2CH2), 3.46 (m, 1H, CHO), 7.19–7.29 (m, 9H, ArH), 7.55–7.53 (m, 6H, ArH); 13C NMR (100
MHz, CDCl3): δ 24.4 (2C), 25.9, 33.9 (2C) [(CH2)5], 72.1 (CHO), 86.5 (CO), 126.9 (3C), 127.7 (6C),
129.1 (6C), 145.8 (3C, ArC); MS m/z (%): 342 (M+, 2), 244 (25), 243 (100), 183 (16), 165 (39), 105
(20).
3.2.8. 5-Trityloxy-2-pentanol (1h).13 White solid; yield 0.82 g (62%); mp 84 °C; IR (cm-1): 3024,
2950, 2862, 1593, 1488, 1045; 1H NMR (250 MHz, DMSO-d6): δ 0.87–1.52 [m, 8H, CH3, 2CH2, and
OH], 3.47-3.56 (m, 2H, CH2O), 3.92-3.99 (m, 1H, CHOH), 7.23–7.37 (m, 9H, ArH), 7.37–7.44 (m,
6H, ArH); 13C NMR (62.5 MHz, DMSO-d6): δ 23.1 (CH3), 33.0, 36.1 [(CH2)2], 66.2 (CH2O), 75.8
(CHOH), 86.3 (CO), 126.9 (3C), 127.8 (6C), 128.4 (6C), 145.0 (3C, ArC); MS m/z (%): 244 (M+-
C5H10O2, 35), 243 (100), 183 (20), 165 (11), 105 (28), 77 (15), 51(7); Anal. Calcd for C24H26O2: C,
83.20; H, 7.56. Found: C, 83.24; H, 7.55.
3.2.9. 1,6-Di(trityloxy)hexane (1i).13 White solid; yield 1.60 g (53%); mp 160 ºC; IR (cm-1): 3000,
3010, 2950, 1450, 1000, 1010; 1H NMR (400 MHz, MeOD-d4): δ 1.30–1.33 [m, 4H,
(CH2CH2CH2O)2], 1.53–1.62 [m, 4H, (CH2CH2CH2O)2], 3.00 [t, 4H, J = 6.6 Hz, (CH2CH2CH2O)2],
7.19–7.29 (m, 18H, ArH), 7.41–7.44 (m, 12H, ArH); 13C NMR: (100 MHz, CDCl3): δ 26.2 (2C),
30.1 (2C) [(CH2)4], 63.6 (2CH2O), 86.3 (2CO), 126.9 (6C), 127.8 (12C), 128.8 (12C), 144.6 (6C,
ArC); MS m/z (%): 259 (3), 245 (4), 244 (31), 243 (100), 241 (2), 183 (4), 165 (20), 105 (13); Anal.
Calcd for C44H42O2: C, 87.67; H, 7.02. Found: C, 87.63; H, 7.03.

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3.2.10. 1,4-Di(trityloxy)pentane(1j).9a White solid; yield 1.62 g (55%); mp 160 °C; IR (cm-1): 3083,
3052, 3022, 1598, 1500, 1081, 1075; 1H NMR (300 MHz, CDCl3): δ 0.88 (d, 3H, J = 6.1 Hz, CH3),
1.04–1.24 (m, 2H, CH2CH2), 1.38–1.69 (m, 2H, CH2CHO), 2.73–2.95 (m, 2H, CH2O), 3.49–3.62 (m,
1H, CHO), 7.08–7.58 (m, 30H, ArH); 13C NMR (75 MHz, CDCl3): δ 21.2 (CH3), 25.5, 34.0 [(CH2)2],
64.0 (CH2O), 69.8 (CHO), 86.4 (CO), 86.6 (CO), 126.9 (3C), 127.7 (3C), 127.8 (6C), 128.0 (6C),
128.8 (6C), 129.1 (6C), 144.6 (3C), 145.6 (3C, ArC); MS (DIP) m/z (%): 588 (M+, 0.5), 244 (70),
243 (100), 165 (56), 105 (28); Anal. Calcd for C43H40O2: C, 87.72; H, 6.85. Found: C, 87.70; H, 6.81.
3.2.11. Geranyl trityl ether (1k).9a Colorless oil; yield 1.75 g (88%); IR (cm-1): 3043, 2920, 2866,
1670, 1596, 1446, 1049; 1H NMR (300 MHz, CDCl3): δ 1.52 (s, 3H, CH3), 1.67 (s, 3H, CH3), 1.75 (s,
3H, CH3), 2.04–2.21 (m, 4H, CH2CH2), 3.67 (d, 2H, J = 6.4 Hz, CH2O), 5.17 [t, 1H, J = 6.4 Hz
HC=C(CH3)2], 5.55–5.46 (m, 1H, CH=CCH2O), 7.24–7.39 (m, 9H, ArH), 7.50–7.56 (m, 6H, ArH);
13C NMR (75 MHz, CDCl3): δ 16.6, 17.8, 25.8 (3CH3), 26.5, 39.7 [(CH2)2], 61.4 (CH2O), 86.7 (CO),
121.5, 124.2 (2CH=C), 126.9 (3C), 127.8 (6C), 127.8 (6C), 131.6, 138.6 (2C=CH), 144.5 (3C, ArC);
MS: m/z (%) = 319 (M+-Ph, 0.5), 244 (39), 243 (100), 165 (34), 105 (11), 69 (11).
3.2.12. Benzyl trityl ether (1l).9a White solid; yield 1.60 g (92%); mp 95 °C; IR (cm-1): 3163, 3031,
2896, 2866, 1593, 1488, 1076; 1H NMR (400 MHz, CDCl3): δ 3.51 (s, 2H, CH2), 7.22–7.34 (m, 14H,
ArH), 7.54–7.58 (m, 6H, ArH); 13C NMR (100 MHz, CDCl3): δ 72.1 (CH2), 86.5 (CO), 126.8 (2C),
127.3 (3C), 127.6, 127.8 (6C), 128.0 (2C), 129.1 (6C), 146.7, 146.9 (3C, ArC); MS m/z (%): 273
(M+-Ph, 3), 245 (18), 244 (100), 243 (85), 167 (11), 166 (16), 165 (68), 105 (51), 91 (88), 77 (27).
3.2.13. Phenyl trityl ether (1m).13 Colorless oil; yield 1.62 g (38%); IR (cm-1): 3166, 3055, 2947,
1593, 1485, 1076; 1H NMR: (250MHz, CDCl3): δ 6.63-6.79 (m, 3H, ArH), 6.94-7.03 (m, 2H, ArH),
7.22–7.31 (m, 9H, ArH), 7.33–7.44 (m, 6H, ArH); 13C NMR (62.5 MHz, CDCl3): δ 86.5 (CO), 122.1
(2C), 122.4 (2C), 128.2 (3C), 128.6 (6C), 129.3 (6C), 145.3 (3C), 146.6 (ArC); MS m/z (%): 274
(20), 243 (55), 198 (14), 197 (100), 167 (20), 166 (16), 165 (65), 152 (9), 105 (35), 77 (26), 51 (5);
Anal. Calcd for C25H20O: C, 89.25; H, 5.99. Found: C, 89.23; H, 5.96.
3.3. General procedure for the detritylation of ethers 1.
Indium powder (0.02 g, 1.7 mmol) was added to a solution of the substrate (0.1 mmol) in
methanol (3 mL) and a saturated ammonium chloride solution (1 mL), and the mixture was heated at
reflux. After the time indicated in table 2, the cooled reaction mixture was then quenched with water
(2.5 mL) and extracted with EtOAc (3 × 5 mL) and the combined organic phases were washed with
brine (2.5 mL) and dried over sodium sulfate. After evaporation of the solvents, the resulting residue
was purified by column chromatography (silica gel, hexane–EtOAc) affording the expected alcohols
2, which were characterized by comparison of their chromatographic and spectroscopic data (NMR)
with commercially available authentic samples. Mass and yields for compounds 2, as well as for trityl
chloride, follow.
3.3.1. 1-Octadecanol (2a). Yield 21.5 mg (80%); Trityl chloride. Yield 18.1 mg (65%).
3.3.2. 1-Hexanol (2b). Yield 7.2 mg (70%).

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3.3.3. 1-Decanol (2c). Yield 11.3 mg (71%).
3.3.4. 3-Methyl-1-butanol (2d). Yield 5.5 mg (62%).
3.3.5. 2-Octanol (2e). Yield 8.9 mg (68%).
3.3.6. Cyclopentanol (2f). Yield 6.5 mg (75%).
3.3.7. Cyclohexanol (2g). Yield 7.0 mg (70%).
3.3.8. 1,4-Pentanediol (2h). Yield 5.8 mg (56%).
3.3.9. 1,6-Hexanediol (2i). Yield 7.1 mg (60%).
3.3.10. 1,4-Pentanediol (2j = 2h). Yield 6.0 mg (58%).
3.3.11. Geraniol (2k). Yield 9.6 mg (62 %).
3.3.12. Benzyl alcohols (2l). Yield 8.9 mg (81%).
3.3.13. Phenol (2m). Yield 6.4 mg (68%).
Acknowledgements
This work was financially supported by the Agence National pour le Développement de la Research
en Santé (Algérie) and the Spanish Ministerio de Ciencia e Innovación (CTQ2011-24155, CTQ2011-
24165), the Ministerio de Economía y Competitividad (CTQ2013-43446-P, CTQ2014-51912-REDC,
CTQ2014-53695-P), FEDER, the Generalitat Valenciana (PROMETEO 2009/039,
PROMETEOII/2014/017), and the University of Alicante. We also thank the Spanish Ministerio de
Asuntos Exteriores y de Cooperación (AP/039112/11.
References and notes
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1999, 55, 11149.

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Behloul, C.; Guijarro, D.; Yus, M. Tetrahedron 2005, 61, 9319; (e) Behloul, C.; Guijarro, D.;
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(vii), 41; (g) Behloul, C.; Chouti, A.; Guijarro, D.; Nájera, C.; Yus, M. Synthesis 2015, 47, 507.
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Synthesis 2016, 48, 2455.
13. We have also studied the use of metallic salts, such as lithium chloride for the detritylation of
trityl ethers: Behloul, C.; Chouti, A.; Chabour, I.; Bengliz, B.; Guijarro, D.; Foubelo, F.; Nájera,
C.; Yus, M. Tetrahedron Lett. 2016, 57, 3526.
14. For other detritylation methodologies, involving triethylsilane,14a low-valent titanium reagents,14b
cerium(IV) ammonium nitrate on silica gel,14c protic14d and Lewis acids14e or bases,14f
electrolytic processes,14g catalytic hydrogenation14h or reduction with sodium in liquid
ammonia14i see, for instance: (a) Imagawa, H.; Tsuchihashi, T.; Sing, R. K.; Yamamoto, H.;

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Sugihara, T.; Nishizawa, M. Org. Lett. 2003, 5, 153; (b) Rele, S.; Nayak, S. K. Synth. Commun.
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GRAPHICAL ABSTRACT