Dario Pasini et al.
FULL PAPERS
(4H, m, -O-CH2-CH2-O-); 13C NMR (75 MHz, CDCl3): d=
138.7, 138.4, 137.7, 129.2, 127.5, 115.2, 74.2, 72.6, 63.1.
Experimental Section
Compound 1b: Prepared from propane-1,3-diol (67.0 g,
0.88 mol), 4-vinylbenzyl chloride (5 g, 0.033 mol), NaOH
(0.033 mol) and H2O (0.033 mol). Purified by column chro-
matography (SiO2; C6H12/AcOEt: 6/4), 1b was obtained as a
yellow-orange oil; yield: 5.6 g (89%). IR: n=3386, 2863,
General Remarks
Monomer and polymer synthesis: All commercially avail-
able compounds were purchased from Aldrich and used as
received. THF (CaH2) and CH2Cl2 (CaH2) were dried and
distilled before use. N,N’-4-Dimethylaminopyridinium p-tol-
uenesulfonate (DPTSA)[11] was prepared according to litera-
ture procedures. Flash chromatography was carried out
using silica gel (Merck 60, 0.040–0.063 mm). 1H and
13C NMR spectra were recorded from solutions in CDCl3 or
CD3COCD3 on Bruker 200 or AMX300 spectrometers with
the solvent residual proton signal or tetramethylsilane
(TMS) as a standard. Infrared spectra were recorded on a
FT-IR PE Paragon 1000 spectrophotometer using potassium
bromide with a diffuse reflectance accessory. Size-exclusion
chromatography was carried out on a Waters system equip-
ped with a DRI detector. Low polydispersity polystyrene
standards (Fluka) were used for the calibration curve and
the mobile phase was tetrahydrofuran (1mL/minute, 40 8C).
A bank of two columns (Styragel 4E and 5E) was used. Ele-
mental analyses were done on a Carlo Erba 1106 elemental
analyzer.
Biocatalysis: Penicillin G acylase crude extract from E.
coli ATCC 11105 (EC 3.5.1.11) was kindly donated by Re-
cordati (Milan, Italy); Eupergit C was kindly donated from
Rohmpharma Rohm GmbH (Darmstadt, Germany); agar-
ose (Sepharose CL-6B) was purchased from Amersham
Pharmacia Biotech (Uppsala, Sweden). Enzymatic activities
were calculated on hydrolysis of penicillin G potassium salt
(pH 8 and 378C) as previously reported.[12] HPLC analyses
were run on a Kontron Instrument AG equipped with UV
detector using a LiChroCART 250–4 RP-18 select-B 5 mm
column, and the following conditions: flow 1mLmin À1; elu-
ents: phosphate buffer 10 mM 70%-CH3CN 30%, pH 5.
During the enzymatic hydrolysis reactions, the pH of the
solutions was kept constant using an automatic titrator 718
Stat Titrino from Metrohm (Herisau, Switzerland). Immobi-
lization of the free enzyme on Eupergit C and on Sepharose
CL-6B was carried out as previously described.[12]
1629, 1511, 1363, 1089 cmÀ1 1H NMR (200 MHz, CDCl3):
;
d=7.5 (4H, dd, ArH), 6.7 (1H, dd, -CH=CH2), 5.7 (1H, d,
-CH=CH2), 5.3 (1H, d, -CH=CH2), 4.5 (2H, s, Ar-CH2-O-),
3.8 (2H, t, -O-CH2-CH2-CH2-OH), 3.7 (2H, m, -O-CH2-
CH2-CH2-OH), 2.75 (1H, s, OH), 1.85 (2H, m, -O-CH 2-
CH2-CH2-OH); 13C NMR (75 MHz, CDCl3): d=137.5, 136.9,
136.3, 127.7, 126.1, 113.7, 72.7, 68.8, 61.2, 32.0; anal. calcd.
for C12H16O2: C 74.9%, H 8.4%; found: C 74.8%, H 8.8%.
Compound 1c: Prepared from butane-1,4-diol (81.5 g,
0.90 mol), 4-vinylbenzyl chloride (5 g, 0.033 mol), NaOH
(0.033 mol) and H2O (0.033 mol). Purified by column chro-
matography (SiO2; C6H12/AcOEt: 8/2), 1c was obtained as a
dark yellow oil; yield: 5.8 g (86%). IR: n=3404, 3086, 2939,
2863, 1711, 1629, 1362, 1100 cmÀ1 1H NMR (200 MHz,
;
CDCl3): d=7.4 (4H, m, ArH), 6.7 (1H, dd, -CH=CH2), 5.8
(1H, d, -CH=CH2), 5.25 (1H, d, -CH=CH2), 4.5 (2H, s, Ar-
CH2-O-), 3.7–3.5 (4H, m, -O-CH2-CH2-CH2-CH2-OH), 2.5
(1H, s, OH), 1.7 (4H, m, -O-CH2-CH2-CH2-CH2-OH);
13C NMR (75 MHz, CDCl3): d=137.5, 136.8, 136.3, 127.7,
126.1, 113.6, 72.6, 70.1, 62.4, 29.9, 24.5; anal. calcd. for
C13H18O2: C 75.7%, H 8.8%; found: C 75.1%, H 9.3%.
General Procedure for the Preparation of Esters 2a–c
A solution of alcohol 1 (12 mmol) in dry CH2Cl2 (10 mL)
was added dropwise over a few minutes to a solution of phe-
nylacetic acid (9 mmol), DICD (11 mmmol) and DPTSA
(5.8 mmol) in dry CH2Cl2 (40 mL). The solution was stirred
for 24 h, then quenched with H2O. The organic layer was
separated, and the aqueous layer was extracted with CH2Cl2
(250 mL). The combined organic layers were dried
(Na2SO4), the suspension filtered and the organic solvent re-
moved under vacuum. The crude product was purified by
column chromatography (SiO2; C6H12/AcOEt).
Compound 2a: Prepared from alcohol 1a (2.05 g,
12 mmol), DICD (1.38 g, 11 mmol), phenylacetic acid
(1.23 g, 9 mmol), DPTSA (1.71 g, 5.8 mmol). Purified by
column chromatography (SiO2; C6H12/AcOEt: 8/2), 2a was
obtained as a yellow oil;yield: 1.95 g (74%); IR: n=2868,
General Procedure for the Preparation of Diols 1a–c
The appropriate diol (0.9 mol) was added to a mixture of 4-
vinylbenzyl chloride (0.033 mol), NaOH (0.038 mol) and
H2O (0.038 mol). The suspension was stirred with a magnet-
ic stirrer at 708C in a thermostated oil bath for 24 h. After
cooling to room temperature, H2O (100 mL) was added and
the solution was extracted with Et2O (3100 mL). The or-
ganic solution was dried (Na2SO4), the suspension filtered
and the organic solvent removed under vacuum. The crude
product was purified by column chromatography (SiO2;
C6H12/AcOEt).
1
1732, 1629, 1257 cmÀ1; H NMR (300 MHz, CDCl3): d=7.25
(9H, m, ArH), 6.75 (1H, dd, -CH=CH2), 5.75 (1H, d, -CH=
CH2), 5.25 (1H, d, -CH=CH2), 4.5 (2H, s, Ar-CH2-O-CH2-),
4.25 (2H, t, -COOCH2-), 3.65 (4H, m, -O-CH2-CH2-O-and
ArCH2COO-); 13C NMR (75 MHz, CDCl3): d=171.3, 137.2–
125.4 (9 signals), 113.7, 76.8, 67.06, 63.5, 41.05; anal. calcd.
for C19H20O3: C 77.0%, H 6.8%; found: C 77.5%, H 7.2%.
Compound 2b: Prepared from alcohol 1b (4.54 g,
23 mmol), DICD (2.66 g, 21mmol), phenylacetic acid
(2.88 g, 21mmol), DPTSA (1.64 g, 5.6 mmol). Purified by
column chromatography (SiO2; C6H12/AcOEt: 8/2), 2b was
obtained as a yellow oil; yield: 4.70 g (72%). IR: n=3030,
Compound 1a: Prepared from ethylene glycol (33.1g,
0.53 mol), 4-vinylbenzyl chloride (3.05 g, 0.02 mol), NaOH
(0.02 mol) and H2O (0.02 mol). Purified by column chroma-
tography (SiO2; C6H12/AcOEt: 7/3), 1a was obtained as a
yellow oil; yield: 2.96 g (84%). IR: n=3417, 3086, 3006,
2860, 1734, 1629, 1511, 1363, 1258, 1103 cmÀ1
;
1H NMR
1
2862, 1629 cmÀ1; H NMR (200 MHz, CDCl3): d=7.50–7.25
(300 MHz, CDCl3): d=7.5 (9H, m, ArH), 6.75 (1H, dd,
(4H, m, ArH), 6.75 (1H, dd, -CH=CH2), 5.75 (1H, d, -CH= -CH=CH2), 5.75 (1H, d, -CH=CH2), 5.25 (1H, d, -CH=
CH2), 5.25 (1H, d, -CH=CH2), 4.5 (2H, s, Ar-CH2-O-), 3.6 CH2), 4.5 (2H, s, Ar-CH2-O-CH2-), 4.25 (2H, t, -COOCH2-),
976
ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 2007, 349, 971– 978