H. Brunner - B. Haßler •Enantioselective Catalysis
479
6.87 (dd, lH,Py-H3), 10.65 (brs, 1H,NH).MS (EI): m/z (dd, 1H, / 34 = 2.7 Hz, J45 = 3.6 Hz, Py-H4), 6.73 (dd, 1H,
= 192 (22, M), 135 (100, M-C4 H9).
735 = 1.4 Hz, Py-H5), 6 . 8 8 (dd, 1H, Py-H3), 7.16-7.34 (m,
5H, Ar-H), 10.34-10.49 (br s, 1H, NH). MS (El): m/z =
226 (5, M), 135 (100, M-C7 H7 ).
C ,|H 16N20 (192.3)
Calcd C 68.72 H 8.39 N 14.57%,
Found C 68.82 H 8.27 N 14.40%.
C|4 Hi4 N20 (226.3)
Calcd C 74.31 H 6.24 N 12.38%,
Found C 74.55 H 6.28 N 12.25%.
(+)-(4S)-4-tert-Butyl-4,5-dihydro-2-(2-pyrrolyl')-
oxazole (8)
(-)-(4S,5R)-4,5-Dihydro-5-methyl-4-phenyl-2-
According to general procedure A with (S)-tert-
leucinol. On addition of 5 ml of CH2C12 unreacted leu-
cinol precipitated and was filtered off. The resulting oil
was treated with ether/PE to yield the product as a red
powder (0.73 g, 3.90 mmol, 39%), m.p. 216-18°C. [ q ] d
= +60° (c = 1.42, CHCI3 ). 'H NMR (CDC13, 250 MHz):
(2-pyrrolyl)oxazole (1 1 )
According to general procedure B with (1R,2S)-
norephedrine. Recrystallization from ether/PE 1:1. White
powder (0.65 g, 2.87 mmol, 29%), m.p. 106-109°C. [alo
= -322° (c = 1.94, CHC13). 'H NMR (CDC13, 250 MHz):
6 = 0.85 (d, 3H, V = 6.9 Hz, CH3), 4.53-4.63 (m, 1H,
Ox-CH), 5.70 (d, 1H, 3/ = 9.5 Hz, Ox-CHt), 6.26 (dd, 1H,
734 = 2.5 Hz, y45 = 3.6 Hz, Py-H4), 6.85 (dd, 1H, / 35 =
1.5 Hz, Py-H5), 6.90 (dd, 1H, Py-H3), 7.23-7.39 (m, 5H,
Ar-H), 10.56 (brs, 1H, NH). MS (El): m/z = 226 (26, M),
120(100, M-C7 H6 0).
6 = 0.94 (s, 9H, C(CH3)3), 3.20 (dd, 1 H,
V h h . = 8 . 8
Hz, 3/hhc = 8 . 8 Hz, Ox-CH), 4.07 (dd, 1H, 2J = 2.8 Hz,
Ox-C//cHt, 4.19 (dd, 1H, Ox-CHcHt), 6.32-6.38 (m, 1H,
Py-H4), 6.74-6.79 (m, 1H, Py-H5), 7.07-7.12 (m, 1H, Py-
H3), 11.36 (br s, 1H, NH). MS (El): m/z = 192 (11, M),
135 (1 0 0 , M-C4 H9).
C,4 Hi4 N20 (226.3)
C ,,H 16N20 (192.3)
Calcd C 74.31 H 6.24 N 12.38%,
Found C 74.43 H 6.28 N 12.17%.
Calcd C 68.72 H 8.39 N 14.57%,
Found C 68.53 H 8.20 N 14.63%.
(+)-(4S,5S)-4,5-Dihydro-4-hydroxymethyl-5-phenyl-2-
(2-pyrrolyl)oxazole ( 12)
(+)-(4R)-4,5-Dihydro-4-phenyl-2-(2-pyrrolyl)oxazole(9)
According to general procedure
A with (R)-
According to general procedure B with (lS,2S)-2-
amino-1,3-propanediol. By cooling the reaction mixture
the product precipitated. White powder (1.29 g, 5.32
mmol, 53%), m.p. 190-191°C. [a]D = +9.6° (c = 0.52,
DMSO). ‘H NMR (d6 -DMSO, 250 MHz): 6 = 3.47-3.56
(m, 1H, CHH'OH), 3.65-3.75 (m, 1H, CH/fOH), 3.98
phenylglycinol. On addition of 5 ml of CH2 CI2 unreacted
phenylglycinol precipitated and was filtered off. The re-
sulting oil was treated with ether to yield the product as
a white powder (0.28 g, 1.32 mmol, 13%), m.p. 93-95°C.
[q]d = +46° (c = 2.82, CHC13). 'H NMR (CDC13, 250
MHz): 6 = 4.22 (dd, 1H, 3 7HHt = 8.3 Hz, 37Hhc = 7.6 Hz,
Ox-CH), 4.72 (dd, 1H, 2J = 9.8 Hz, OC//cHt), 5.31 (dd,
1H, Ox-CHc//t), 6.13 (dd, 1H, 734 = 3.6 Hz, J45 = 2.6 Hz,
(ddd, 1H, V = V = 4.2Hz, 37
h
h
c
= 6.1 Hz, Ox-CH), 5.01
(t, 1H, J = 5.5 Hz, OH), 5.46 (d, 1H, Ox-CHc), 6.14-6.20
(m, 1H, Py-H4), 6.63-6.69 (m, 1H, Py-H5), 6.92-6.97 (m,
1H, Py-H3), 7.31-7.43 (m, 5H, Ar-H), 11.75 (s, 1H, NH).
MS (El): m/z = 242 (17, M), 211 (100, M-CH2 OH).
Py-H4), 6.26 (dd, lH, 35 = 1.5 Hz, Py-H5), 6.77 (dd, 1H,
/
Py-H3), 7.24-7.40 (m, 5H, Ar-H), 10.77 (br s, 1H, NH).
MS (El): m/z =212 (100, M), 135 (14, M-C6 H5).
C,4 H,4 N2 0 2 (242.3)
C13H,2 N20 (212.3)
Calcd C 69.40 H 5.82 N 11.56%,
Found C 69.30 H 5.82 N 11.66%.
Calcd C 73.57 H 6.79 N 13.20%,
Found C 73.28 H 6.85 N 13.52%.
(-)-(4S)-4,5-Dihydro-4-hydroxydiphenylmethyI-2-
(2-pyrrolyl)oxazole (13)
(+)-(4S)-4-Benzyl-4,5-dih.ydro-2-(2-pyrrolyl)oxazole (10)
According to general procedure
B
with (S)-
According to general procedure
B with (2S)-
phenylalaninol. Recrystallization from ether/PE 1:1. 2-amino-1,1-diphenyl-1,3-propanediol. Purification by
White powder (1.31 g, 5.79 mmol, 58%), m.p. 65-68°C.
[a h = +14° (c = 2.21, CHC13). 'H NMR (CDC13, 250
MHz): 6 = 2.73 (dd, 1H, V = 8 . 6 Hz, 2J = 15.5 Hz,
C//H'Ph), 3.16 (dd, 1H, 3J = 5.3 Hz, CH/f Ph), 4.10 (dd,
1H, V = 7.1 Hz, 2J = 8.5 Hz, Ox-C//cHt), 4.32 (dd, 1H,
V = 8.5 Hz, Ox-CHc//t), 4.48-4.60 (m, 1H, Ox-CH), 6.23
chromatography (silica gel, EE/PE 1:1). Recrystallization
from EE/PE 1:2. Colourless crystals (0.90 g, 2.83 mmol,
28%), m.p. 128-129°C. [q]d = -13° (c = 1.29, CH2 C12).
'H NMR (CDC13, 250 MHz): 6 = 3.10 (br s, 1H, OH),
4.01 -4.12 (m, 2H, Ox-CHcH,), 5.36 (dd, 1H, 37Hhc= 3/ h h ,
= 9.3 Hz, Ox-CH), 6.18 (dd, 1H, 734 = 3.5 Hz, J45= 2.6 Hz,
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Download Date | 7/8/15 4:20 PM