Lipozyme-Mediated Regioselective Esterification of Isosorbide Under Solvent-Free Conditions

Abstract

Abstract: Monoesters of isosorbide were obtained with high regioselectivity in Lipozyme catalysed esterification by fatty acids under solvent-free conditions.

Notes

Novozym and Lipozyme were a gift from Novo Nordisk.

Table 2: GC Retention times (min) of esters of isosorbide. GC analyses were performed on a Fisons Instruments GC 8000 series chromatograph with flame ionization and capillary column OV 1 12m, ID 0.22 mm, ef 0.1 pm, (carrier gas He at 70kPa) with the same gradient for the products a, b, c, d: 100°C to 270°C (10°C/min) then 270°C. For the products e the conditions were: 100°C to 280°C (10°C/min) then 280°C during 35 min. The retention time of isosorbide was 2,43 min. Internal standard for calibration in GC was methyl myristate.

¹H NMR spectra were recorded on Brüker 250 MHz spectrometer in CDCl₃ with TMS as an internal standard. The optical rotations were measured at 20 °C on P20 Bellingham+Stanley Ltd. Polarimeter.

3a: [α]_D=+86.6 (c 1 CH₃OH)

¹H-NMR (CDCl₃): 0.8-0,95 (3H, t, CH₃); 1,15-1,42 (8H, m, 4CH₂); 1,54-1,73 (2H, m, CH₂); 2,27-2,33 (1H, d, OH); 2,33-2,43 (2H, t, CH₂); 3,72-3,82 (1H, q, H6a); 3,85-3,97 (3H, m, H1a, 1b, 6b); 4,28-4,37 (1H, broad,H2); 4,37-4,43 (1H, d, H3); 4,81-4,89 (1H, t, H4); 5,1-5,2 (1H, q, H5).

3b: [α]_D=+78.2 (c 1 CH₃OH)

¹H-NMR (CDCl₃): 0,8-0,95 (3H, t, CH₃); 1,15-1,4 (12H, m, 6CH₂); 1,55-1,72 (2H, m, CH₂); 2,27-2,34 (1H, broad, OH); 2,32-2,42 (2H, t, CH₂); 3,72-3,81 (1H, q, H6a); 3,85-3,96 (3H, m, H1a, 1b, 6b); 4,28-4,37 (1H, broad, H2); 4,37-4,43 (1H, d, H3); 4,82-4,89 (1H, t, H4); 5,1-5,19 (1H, q, H5).

3c: [α]_D=+72.6 (c 1 CH₃OH), mp=21-22°C

¹H-NMR (CDCl₃): 0,8-0,93 (3H, t, CH₃); 1,15-1,42 (16H, m, 8CH₂); 1,55-1,78 (2H, m, CH₂); 2,32-2,42 (2H, t, CH₂); 3,72-3,82 (1H, q, H6a); 3,85-3,98 (3H, m, H1a, 1b, 6b); 4,3-4,38 (1H, broad, H2); 4,38-4,44 (1H, d, H3); 4,81-4,89 (1H, t, H4); 5,11-5,2 (1H, q, H5).

3d: [α]_D=+65.0 (c 1 CH₃OH), mp=37-38¶C

¹H-NMR (CDCl₃): 0,8-1 (3H, t, CH₃); 1,15-1,45 (20H, m, 10CH₂); 1,5-1,8 (2H, m, CH₂); 2,3-2,45 (2H, t, CH₂); 3,72-3,82 (1H, q, H6a); 3,87-3,98 (3H, m, H1a, 1b, 6b); 4,3-4,38 (1H, broad, H2); 4,38-4,45 (1H, d, H3); 4,81-4,9 (1H, t, H4); 5,1-5,22 (1H, q, H5).

3e: [α)_D=+62.8 (c 1 CH₃OH), mp=48.5-49.5°C

¹H-NMR (CDCl₃): 0,8-0,95 (3H, t, CH₃); 1,15-1,45 (24H, m, 12CH₂); 1,55-1,75 (2H, m, CH₂); 2,3-2,43 (2H, t, CH₂); 3,72-3,83 (1H, q, H6a); 3,85-3,98 (3H, m, H1a, 1b, 6b); 4,3-4,38 (1H, broad, H2); 4,38-4,45 (1H, d, H3); 4,82-4,9 (1H, t, H4); 5,12-5,22 (1H, q, H5).

Mass analyses were performed on NERMAG R10–10 equipped with CPSil-5, 25m capillary column.