K. R. Prasad, A. Chandrakumar / Tetrahedron 63 (2007) 1798–1805
1803
J¼8.1 Hz), 4.86 (dd, 1H, J¼6.9, 3.9 Hz), 4.77 (dd, 1H,
J¼6.9, 3.9 Hz), 4.41 (d, 1H, J¼6.9 Hz), 3.41 (d, 1H,
J¼6.9 Hz), 3.02 (s, 3H), 2.89 (s, 3H), 2.33 (s, 3H), 1.41 (s,
3H), 1.39 (s, 3H); 13C NMR (75 MHz, CDCl3) d 168.9,
137.4, 137.3, 128.8, 126.6, 110.7, 81.2, 74.5, 72.3, 37.0,
35.8, 26.9, 26.2, 21.1. Analysis calcd for C16H23NO4: C,
65.51; H, 7.90; N, 4.77. Found: C, 65.47; H, 7.91; N, 4.70.
5.1 Hz), 4.13 (d, 1H, J¼5.4 Hz), 1.83–1.39 (m, 6H), 0.94
(t, 3H, J¼7.2 Hz); 13C NMR (75 MHz, CD3OD) d 177.4,
83.5, 74.9, 74.6, 29.5, 29.0, 23.6, 14.3. Analysis calcd for
C8H14O4: C, 55.16; H, 8.10. Found: C, 54.92; H, 8.02.
4.6.4. (2R,3S,4R)-2,3-Dihydroxy-4-octylbutyrolactone
(4d). Yield 98%; white solid; mp 68–70 ꢀC (lit.5b mp 68–
70 ꢀC); Rf 0.4 (7:3 ethyl acetate/petroleum ether); [a]D +72
(c 1, CHCl3), lit.5b [a]D ꢁ71.9 (c 0.78, CHCl3 for the other
enantiomer); IR (KBr): 3433, 2924, 1777, 1466, 1152,
4.5.3. (4R,5S)-5-((R)-Hydroxy(p-anisyl)methyl)-2,2,N,N-
tetramethyl-1,3-dioxolane-4-carboxamide (3j). Yield
87%; white needles; mp 147.3–147.7 ꢀC; Rf (60% ethyl ace-
tate/petroleum ether) 0.3; [a]D ꢁ23.1 (c 1.6, CHCl3); IR
1
975 cmꢁ1; H NMR (300 MHz, CD3OD) d 4.57–4.50 (m,
1H), 4.18 (dd, 1H, J¼5.4, 4.8 Hz), 4.13 (d, 1H, J¼5.4 Hz),
1.79–1.73 (m, 1H), 1.64–1.31 (m, 13H), 0.90 (t, 3H, J¼
6.9 Hz); 13C NMR (75 MHz, CD3OD) d 177.4, 83.5, 74.9,
74.6, 33.0, 30.6, 30.4, 29.8, 26.8, 23.7, 14.4. Analysis calcd
for C12H22O4: C, 62.58; H, 9.63. Found: C, 62.50; H, 9.49.
(KBr): 3423, 2938, 1647, 1514, 1250, 1062 cmꢁ1 1H
;
NMR (300 MHz, CDCl3) d 7.35 (d, 2H, J¼9.0 Hz), 6.88
(d, 2H, J¼9.0 Hz), 4.86 (dd, 1H, J¼6.9, 4.2 Hz), 4.76 (d,
1H, J¼4.2 Hz), 4.39 (d, 1H, J¼6.9 Hz), 3.80 (s, 3H), 3.38
(br s, 1H), 3.03 (s, 3H), 2.90 (s, 3H), 1.41 (s, 3H), 1.40 (s,
3H); 13C NMR (75 MHz, CDCl3) d 168.9, 159.2, 132.5,
128.0, 113.6, 110.7, 81.2, 74.6, 72.3, 55.2, 37.0, 35.8,
26.9, 26.3. Analysis calcd for C16H23NO5: C, 62.12; H,
7.49; N, 4.53. Found: C, 62.04; H, 7.51; N, 4.50.
4.6.5. (2R,3S,4R)-2,3-Dihydroxy-4-isopropylbutyro-
lactone (4e). Yield 95%; colourless oil; Rf 0.4 (7:3 ethyl ace-
tate/petroleum ether); [a]D +86 (c 0.5, MeOH); IR (neat):
1
3452, 2954, 1770, 1471, 976 cmꢁ1; H NMR (300 MHz,
CD3OD) d 4.21 (dd, 1H, J¼9.0, 3.9 Hz), 4.15 (dd, 1H,
J¼3.9, 2.4 Hz), 4.03 (d, 1H, J¼2.4 Hz), 2.23–2.01 (m,
1H), 1.06 (d, 3H, J¼6.9 Hz), 0.98 (d, 3H, J¼6.9 Hz);
13C NMR (75 MHz, CD3OD) d 177.8, 90.0, 76.0, 74.1,
28.2, 19.8, 18.2; HRMS for C7H12O4+Na calcd, 183.0633;
found, 183.0630.
4.6. General procedure for preparation of (2R,3S,4R)-
2,3-dihydroxy-4-alkyl (aryl) butyrolactone (4a–j)
To a solution of hydroxyamide 3a–j (0.5 mmol) in dry benz-
ene (5 mL) was added p-toluenesulfonic acid monohydrate
(0.10 g, 0.55 mmol) and stirred for 0.5 h at 45 ꢀC. The reac-
tion mixture was cooled to room temperature and K2CO3
(0.08 g) was added and stirred for 10 min. The reaction mix-
ture was filtered through a pad of Celite and the Celite pad
was washed with EtOAc (20 mL). The filtrate was concen-
trated and the residue was purified by silica gel column
chromatography using petroleum ether and ethyl acetate as
eluent to afford (2R,3S,4R)-2,3-dihydroxy-4-alkyl (aryl)
butyrolactone (4a–j).
4.6.6. (2R,3S,4R)-2,3-Dihydroxy-4-tetradecylbutyro-
lactone (4f). Yield 94%; white solid; mp 87–89 ꢀC; Rf 0.5
(7:3 ethyl acetate/petroleum ether); [a]D +56.6 (c 1.2,
MeOH); IR (KBr): 3408, 2918, 1774, 1469, 1155,
1
982 cmꢁ1; H NMR (300 MHz, CD3OD) d 4.56–4.50 (m,
1H), 4.18 (dd, 1H, J¼5.4, 5.1 Hz), 4.12 (d, 1H, J¼5.4 Hz),
1.79–1.41 (m, 2H), 1.42–1.28 (m, 24H), 0.89 (t, 3H,
J¼6.6 Hz); 13C NMR (75 MHz, CD3OD) d 177.4, 83.5,
74.9, 74.6, 33.1, 30.8, 30.7, 30.6, 30.5, 30.4, 29.8, 26.8,
23.7, 14.5. Analysis calcd for C18H34O4: C, 68.75; H,
10.90. Found: C, 68.81; H, 11.04.
4.6.1. (2R,3S,4R)-2,3-Dihydroxy-4-methylbutyrolactone
(4a). Yield 92%; colourless oil; Rf 0.4 (7:3 ethyl acetate/
petroleum ether); [a]D +77 (c 1, MeOH), lit.4f [a]D +77.2
(c 2.4, MeOH); IR (neat): 3399, 2917, 1773, 1513, 1148,
4.6.7. (2R,3S,4R)-2,3-Dihydroxy-4-cyclohexylbutyro-
lactone (4g). Yield 93%; white solid; mp 137–138 ꢀC; Rf
0.4 (7:3 ethyl acetate/petroleum ether); [a]D +12.8 (c 0.7,
MeOH); IR (KBr): 3448, 2924, 1763, 1722, 1226, 1049,
1051, 952 cmꢁ1 1H NMR (300 MHz, CD3OD) d 4.72–
;
4.67 (m, 1H), 4.20–4.18 (m, 2H), 1.34 (d, 3H, J¼6.6 Hz);
13C NMR (75 MHz, CD3OD) d 177.3, 79.3, 75.1, 74.2,
14.8. Analysis calcd for C5H8O4: C, 45.46; H, 6.10. Found:
C, 45.20; H, 6.14.
1
977 cmꢁ1; H NMR (300 MHz, CD3OD) d 4.26 (dd, 1H,
J¼9.3, 3.9 Hz), 4.14 (dd, 1H, J¼3.9, 2.4 Hz), 4.01 (d, 1H,
J¼2.4 Hz), 1.98–1.68 (m, 6H), 1.39–1.00 (m, 5H); 13C
NMR (75 MHz, CD3OD) d 177.8, 88.9, 75.8, 73.9, 37.5,
30.8, 29.0, 27.4, 26.7, 26.6. Analysis calcd for C10H16O4:
C, 59.98; H, 8.05. Found: C, 60.04; H, 8.24.
4.6.2. (2R,3S,4R)-2,3-Dihydroxy-4-ethylbutyrolactone
(4b). Yield 95%; colourless oil; Rf 0.4 (7:3 ethyl acetate/
petroleum ether); [a]D +84 (c 1, MeOH), lit.4f [a]D +84.6
(c 1.02, MeOH); IR (neat): 3402, 2974, 1773, 1147,
1
968 cmꢁ1; H NMR (300 MHz, CD3OD) d 4.49–4.43 (m,
4.6.8. (2R,3S,4R)-2,3-Dihydroxy-4-phenylbutyrolactone
(4h). Yield 99%; white solid; mp 93.5–95 ꢀC; Rf 0.4 (7:3
ethyl acetate/petroleum ether); [a]D +31.4 (c 0.7, MeOH);
1H), 4.20 (t, 1H, J¼5.4 Hz), 4.13 (d, 1H, J¼5.4 Hz), 1.89–
1.57 (m, 2H), 1.02 (t, 3H, J¼7.5 Hz); 13C NMR (75 MHz,
CD3OD) d 177.4, 84.8, 74.8, 74.6, 23.0, 10.3; HRMS for
C6H10O4+Na calcd, 169.0477; found, 169.0477.
IR (KBr): 3419, 2925, 1763, 1454, 1115, 991 cmꢁ1
;
1H NMR (300 MHz, CD3OD) d 7.40–7.29 (m, 5H), 5.66
(d, 1H, J¼5.4 Hz), 4.40 (t, 1H, J¼5.4 Hz), 4.22 (d, 1H,
J¼5.4 Hz); 13C NMR (75 MHz, CD3OD) d 177.3, 136.1,
129.2, 127.8, 84.0, 75.8, 74.3. Analysis calcd for
C10H10O4: C, 61.85; H, 5.19. Found: C, 61.73; H, 5.51.
4.6.3. (2R,3S,4R)-2,3-Dihydroxy-4-n-butylbutyrolactone
(4c). Yield 96%; white solid; mp 63.5–64.5 ꢀC (lit.4f mp
74–76 ꢀC); Rf 0.4 (7:3 ethyl acetate/petroleum ether); [a]D
+91 (c 1, CHCl3), lit.4f [a]D +91.5 (c 1, CHCl3); IR (KBr):
1
3409, 2958, 1768, 1147, 982 cmꢁ1; H NMR (300 MHz,
4.6.9. (2R,3S,4R)-2,3-Dihydroxy-4-tolylbutyrolactone
(4i). Yield 94%; white solid; mp 96.5–100.5 ꢀC; Rf 0.4
CD3OD) d 4.56–4.50 (m, 1H), 4.18 (dd, 1H, J¼5.4,