Molecules 2011, 16
5014
3.2.5. (+)-2,2-Pentamethylene-1-phenyl-1,3-propanediol 3-O-pivaloate (4bb)
1H-NMR (CDCl3): δ 1.22 (s, 9H, C(CH3)3), 1.34-1.58 (m, 10H, CCH2C), 2.54 (brs, 1H, OH), 3.94
(d, 1H, J = 11.4 Hz, OCH2), 4.21 (d, 1H, J = 11.4 Hz, OCH2), 4.62 (s, 1H, PhCH), 7.25–7.32 (m, 5H,
ArH). 13C-NMR: δ 21.2, 21.4, 25.8, 27.2, 28.2, 28.3, 38.9, 41.1, 64.9, 78.5, 127.3, 127.6, 127.7, 140.9,
178.3. IR (KBr): 3498, 1711 cm−1. MS (FAB, NBA+NaI): m/z 287, 327 ([M+Na]+). HRMS: calcd for
C19H28O3Na 327.1936, found 327.1929. HPLC (Daicel Chiralpak AD-H, hex/IPA = 49/1, 1 mL/min)
tR: 28.1 (minor), 33.0 (major) min. [α]17D +6.0 (c 1.36, CHCl3) for 83% ee.
3.2.6. (+)-2,2-Pentamethylene-1-phenyl-1,3-propanediol 1-O-pivaloate (5bb)
1H-NMR (CDCl3): δ 1.12-1.59 (m, 9H, CCH2C), 1.24 (s, 9H, C(CH3)3), 1.69–1.72 (m, 1H,
CCH2C), 2.07 (brs, 1H, OH), 3.49 (d, 1H, J = 11.9 Hz, OCH2), 3.63 (d, 1H, J = 11.9 Hz, OCH2), 5.78
(s, 1H, PhCH), 7.26–7.33 (m, 5H, ArH). 13C-NMR: δ 21.1, 21.3, 25.9, 27.2, 28.2, 28.4, 39.0, 41.9, 62.9,
79.8, 127.7, 127.8, 127.9, 137.3, 177.6. IR (neat): 3513, 1732 cm−1. MS (FAB, NBA+NaI): m/z 57, 91,
305 ([M+H]+). HRMS: calcd for C19H29O3 305.2117, found 305.2128. [α]17D +23.3 (c 1.47, CHCl3).
3.2.7. (S)-2,2,4-Trimethyl-1,3-pentanediol 1-O-benzoate (4ca)
1H-NMR (CDCl3): δ 0.97 (d, 3H, J = 6.9 Hz, CH(CH3)2), 1.02 (d, 3H, J = 6.9 Hz, CH(CH3)2), 1.05
(s, 3H, C(CH3)2), 1.07 (s, 3H, C(CH3)2), 1.97–2.00 (m, 2H, OH, CH(CH3)2), 3.38 (s, 1H, CHOH), 4.02
(d, 1H, J = 11 Hz, CH2), 4.38 (d, 1H, J = 11 Hz, CH2), 7.43–7.47 (m, 2H, ArH), 7.55–7.59 (m, 1H,
ArH), 8.03–8.05 (m, 2H, ArH). 13C-NMR: δ 17.9, 19.7, 22.3, 23.0, 28.6, 40.3, 70.0, 80.3, 128.5, 129.8,
129.9, 133.2, 167.6. IR (KBr): 3340, 1724 cm−1. MS (FAB, NBA+NaI): m/z 77, 105, 273 ([M+Na]+).
HRMS calcd for C15H22O3Na 273.1467, found 273.1458. HPLC (Daicel Chiralpak AD-H, hex/IPA = 39/1,
1.0 mL/min) tR: 14.4 (S), 15.7 (R) min. [α]17 +9.5 (c 2.14, benzene) for 93% ee, (S). The absolute
D
configuration of 4ca was determined by conversion to diol 6a. [α]29 −11.3 (c 1.54, CH2Cl2) for 93%
D
ee. [lit. 40: [α]30D −9.5 (c 1.0, CH2Cl2) for 75% ee, (S)].
3.2.8. (S)-2,2,4-Trimethyl-1,3-pentanediol 3-O-benzoate (5ca)
1H-NMR (CDCl3): δ 0.95 (s, 3H, C(CH3)2), 1.01 (d, 3H, J = 6.9 Hz, CH(CH3)2), 1.09 (d, 3H, J = 6.9 Hz,
CH(CH3)2), 1.10 (s, 3H, C(CH3)2), 2.17–2.21 (m, 1H, CH(CH3)2), 2.79 (brs, 1H, OH), 3.09 (d, 1H,
J = 11.9 Hz, CH2), 3.34 (d, 1H, J = 11.9 Hz, CH2), 5.04 (d, 1H, J = 2.8 Hz, OCH), 7.45–7.49 (m, 2H,
ArH), 7.58–7.61 (m, 1H, ArH), 8.08–8.10 (d, 2H, J = 7.3 Hz, ArH). 13C-NMR: δ 17.9, 19.7, 22.3, 23.0,
28.6, 40.3, 70.0, 80.3, 128.5, 129.8, 129.9, 133.2, 167.6. IR (neat): 3493, 1720 cm−1. MS (FAB,
NBA+NaI): m/z 105, 273 ([M+Na]+). HRMS calcd for C H O Na 273.1467, found 273.1447. HPLC
:
15 22
3
(Daicel Chiralpak AD-H, hex/IPA = 39/1, 1 mL/min) tR: 13.5 (S), 14.8 (R) min. [α]17 −15.4 (c 1.15,
D
CHCl3) for 93% ee, (S).
Treatment of 4ca (93% ee) with 10 mol % of 1d for 3 h at rt afforded 5ca (32% yield, 92% ee) with
unreacted 4ca (63% yield, 93% ee). Treatment of 5ca (93% ee) with 10 mol % of 1d for 3 h at r.t.
afforded 4ca (58% yield, 93% ee) with unreacted 5ca (32% yield, 93% ee).