420 Bull. Chem. Soc. Jpn., 76, No. 2 (2003)
Preparation of Unsymmetrical Double Aldols
Phenyl[(4RS,5RS,6RS)-2,2,4-trimethyl-6-phenethyl-1,3-di-
oxan-5-yl]methanone (14cAc-B). IR (neat, cm−1) 2947, 1673,
1450, 1373, 1211, 995; H NMR (CDCl3) δ 7.90–7.89 (m, 2H),
5.7, 8.8 Hz, 1H), 3.55 (dd, J = 5.7, 9.9 Hz, 1H), 1.78–1.67 (m,
1H), 1.50 (s, 3H), 1.37 (s, 3H), 0.91 (d, J = 6.4 Hz, 3H), 0.83 (d, J
= 7.2 Hz, 3H), 0.60 (d, J = 6.6 Hz, 3H); 13C NMR (CDCl3) δ
201.5, 138.6, 133.0, 128.7, 128.1, 128.0, 101.3, 53.4, 37.3, 28.8,
24.0, 23.8, 19.8, 18.8, 18.7, 13.7; HRMS m/z calcd for
C17H24O3Na [M + Na]+ 299.1623, found 299.1617.
1
7.58–7.42 (m, 3H), 7.24–7.02 (m, 5H), 4.40 (dt, J = 6.2, 9.0 Hz,
1H), 4.06 (dq, J = 2.9, 6.8 Hz, 1H), 3.70 (dd, J = 6.8, 9.0 Hz,
1H), 2.80–2.71 (m, 1H), 2.53–2.46 (m, 1H), 1.80–1.70 (m, 2H),
1.54 (s, 3H), 1.38 (s, 3H), 1.16 (d, J = 6.2 Hz, 3H); 13C NMR
(CDCl3) δ 200.6, 141.3, 138.4, 133.2, 128.7, 128.4, 128.3, 128.2,
128.1, 128.0, 125.8, 101.0, 68.1, 37.0, 55.5, 33.3, 32.0, 24.8, 24.4,
20.8; HRMS m/z calcd for C22H26O3Na [M + Na]+ 361.1780,
found 361.1786.
[(4RS,5RS,6SR)-4-Isopropyl-2,2,6-trimethyl-1,3-dioxan-5-
yl]phenylmethanone (14dAc-D). IR (neat, cm−1) 2978, 1682,
1
1458, 1373, 1196, 987; H NMR (CDCl3) δ 7.97–7.94 (m, 2H),
7.58–7.36 (m, 3H), 4.32 (dq, J = 3.0, 6.6 Hz, 1H), 3.61–3.57 (m,
2H), 1.74–1.55 (m, 1H), 1.59 (s, 3H), 1.49 (s, 3H), 1.12 (d, J =
6.6 Hz, 3H), 0.93 (d, J = 6.4 Hz, 3H), 0.72 (d, J = 6.6 Hz, 3H);
13C NMR (CDCl3) δ 198.5, 139.7, 132.5, 128.6, 127.8, 98.9, 67.1,
45.2, 30.4, 29.7, 20.1, 19.6, 18.9, 18.3; HRMS m/z calcd for
C17H24O3Na [M + Na]+ 299.1623, found 299.1620.
Phenyl[(4RS,5SR,6SR)-2,2,4-trimethyl-6-phenethyl-1,3-di-
oxan-5-yl]methanone (14cAc-D). IR (neat, cm−1) 2947, 1682,
1
1450, 1373, 1203, 995; H NMR (CDCl3) δ 7.92–7.89 (m, 2H),
7.55–7.41 (m, 3H), 7.24–7.05 (m, 5H), 4.26 (dq, J = 3.1, 6.6 Hz,
1H), 4.06 (ddd, J = 3.1, 3.4, 3.5 Hz, 1H), 3.40 (t, J = 3.1 Hz, 1H),
2.78–2.69 (m, 1H), 2.63–2.53 (m, 1H), 1.90–1.77 (m, 2H), 1.62–
1.51 (m, 2H), 1.62 (s, 3H), 1.48 (s, 3H), 1.10 (d, J = 6.6 Hz, 3H);
13C NMR (CDCl3) δ 198.7, 141.3, 139.8, 132.6, 128.6, 128.5,
128.2, 127.8, 125.7, 99.0, 69.5, 66.8, 47.1, 35.1, 31.4, 29.7, 19.6,
19.0; HRMS m/z calcd for C22H26O3Na [M + Na]+ 361.1780,
found 361.1783.
[(4RS,5SR,6RS)-2,2-Dimethyl-4-phenethyl-6-propyl-1,3-di-
oxan-5-yl]phenylmethanone (14eAc-B). IR (neat, cm−1) 2954,
1
1674, 1458, 1373, 1227, 995; H NMR (CDCl3) δ 7.93–7.90 (m,
2H), 7.59–7.44 (m, 3H), 7.26–7.02 (m, 5H), 4.28 (dt, J = 3.5, 9.0
Hz, 1H), 4.05 (ddd, J = 2.6, 6.4, 10.3 Hz, 1H), 3.72 (dd, J = 6.4,
9.0 Hz, 1H), 2.81–2.71 (m, 1H), 2.52–2.42 (m, 1H), 1.76–1.64 (m,
1H), 1.53 (s, 3H), 1.37 (s, 3H), 1.50–1.20 (m, 5H), 0.82 (t, J = 7.0
Hz, 3H); 13C NMR (CDCl3) δ 200.9, 133.7, 128.5, 128.3, 125.7,
101.7, 100.8, 71.1, 68.4, 37.4, 24.5, 14.0; HRMS m/z calcd for
C24H30O3Na [M + Na]+ 389.2093, found 389.2093.
Phenyl[(4RS,5RS,6SR)-2,2,4-trimethyl-6-phenyl-1,3-diox-
an-5-yl]methanone (14aAc-B). IR (neat, cm−1) 2978, 1689,
1458, 1373; 1H NMR (CDCl3) δ 7.50–6.90 (m, 10H), 5.26 (d, J =
7.0 Hz, 1H), 4.64 (dq, J = 6.2, 9.0 Hz, 1H), 4.02 (dd, J = 7.0, 9.0
Hz, 1H), 1.64 (s, 3H), 1.46 (s, 3H), 1.27 (d, J = 6.2 Hz, 3H);
13C NMR (CDCl3) δ 200.1, 132.3, 128.5, 128.0, 127.9, 127.8,
127.7, 127.6, 127.3, 126.5, 126.1, 101.5, 71.0, 66.4, 57.6, 24.6,
24.3, 21.0; HRMS m/z calcd for C20H22O3Na [M + Na]+
333.1467, found 333.1468.
Phenyl[(4RS,5SR,6RS)-2,2,4-trimethyl-6-phenyl-1,3-diox-
an-5-yl]methanone (14aAc-D). IR (neat, cm−1) 2978, 1689,
1458, 1373; 1H NMR (CDCl3) δ 7.50–7.00 (m, 10H), 5.30 (d, J =
3.3 Hz, 1H), 4.49 (dq, J = 6.4, 3.3 Hz, 1H), 3.74 (t, J = 3.3 Hz,
1H), 1.72 (s, 3H), 1.61 (s, 3H), 1.17 (d, J = 6.4 Hz, 3H);
13C NMR (CDCl3) δ 198.2, 140.0, 139.3, 131.9, 128.1, 128.0,
127.4, 127.3, 126.9, 125.9, 99.4, 72.9, 67.0, 49.6, 29.7, 19.7, 19.1;
HRMS m/z calcd for C20H22O3Na [M + Na]+ 333.1467, found
333.1465.
[(4RS,5RS,6SR)-2,2-Dimethyl-4-phenethyl-6-propyl-1,3-di-
oxan-5-yl]phenylmethanone (14eAc-D). IR (neat, cm−1) 2954,
1
1682, 1450, 1373, 1196, 941; H NMR (CDCl3) δ 7.92–7.89 (m,
2H), 7.54–7.40 (m, 3H), 7.24–7.05 (m, 5H), 4.07–4.04 (m, 2H),
3.40 (t, J = 3.0 Hz, 1H), 2.77–2.54 (m, 2H), 1.87–1.74 (m, 1H),
1.62 (s, 3H), 1.46 (s, 3H), 1.70–1.20 (m, 5H), 0.76 (t, J = 7.0 Hz,
3H); 13C NMR (CDCl3) δ 198.9, 141.3, 139.7, 132.6, 128.1,
127.8, 125.7, 99.0, 70.8, 69.6, 46.4, 35.5, 35.2, 31.4, 29.7, 19.0,
18.7, 13.4; HRMS m/z calcd for C24H30O3Na [M + Na]+
389.2093, found 389.2095.
[(4RS,5SR,6RS)-4-Isopropyl-2,2-dimethyl-6-propyl-1,3-di-
oxan-5-yl]phenylmethanone (14fAc-B). IR (neat, cm−1) 2985,
1
1674, 1450, 1373, 1227, 980; H NMR (CDCl3) δ 7.93–7.90 (m,
2H), 7.59–7.44 (m, 3H), 7.26–7.02 (m, 5H), 4.28 (dt, J = 3.5, 9.0
Hz, 1H), 4.05 (ddd, J = 2.6, 6.4, 10.3 Hz, 1H), 3.72 (dd, J = 6.4,
9.0 Hz, 1H), 2.81–2.71 (m, 1H), 2.52–2.42 (m, 1H), 1.76–1.64 (m,
1H), 1.53 (s, 3H), 1.37 (s, 3H), 1.50–1.20 (m, 5H), 0.82 (t, J = 7.0
Hz, 3H); 13C NMR (CDCl3) δ 201.5, 138.6, 133.0, 128.7, 128.1,
128.0, 101.3, 72.1, 53.4, 37.3, 28.8, 24.0, 23.8, 13.7, 19.8, 18.8,
13.7; HRMS m/z calcd for C19H28O3Na [M + Na]+ 327.1936,
found 327.1944.
[(4RS,5SR,6RS)-4-Ethyl-2,2,6-trimethyl-1,3-dioxan-5-yl]-
phenylmethanone (14bAc-B). IR (neat, cm−1) 2976, 1666,
1
1450, 1373; H NMR (CDCl3) δ 7.95–7.91 (m, 2H), 7.60–7.44
(m, 3H), 4.42 (dq, J = 6.2 , 9.2 Hz, 1H), 4.00 (dt, J = 3.7, 6.6 Hz,
1H), 3.74 (dd, J = 6.6, 9.2 Hz, 1H), 1.52 (s, 3H), 1.39 (s, 3H),
1.45–1.20 (m, 2H), 1.20 (d, J = 6.2 Hz, 3H), 0.83 (t, J = 7.3 Hz,
3H); 13C NMR (CDCl3) δ 200.6, 138.5, 133.1, 128.7, 128.3,
128.1, 100.9, 70.8, 66.8, 55.6, 25.0, 24.5, 24.3, 20.8, 10.7; HRMS
m/z calcd for C16H22O3Na [M + Na]+ 285.1467, found 285.1468.
[(4RS,5RS,6SR)-4-Ethyl-2,2,6-trimethyl-1,3-dioxan-5-yl]-
phenylmethanone (14bAc-D). IR (neat, cm−1) 2978, 1681,
[(4RS,5RS,6SR)-4-Isopropyl-2,2-dimethyl-6-propyl-1,3-di-
oxan-5-yl]phenylmethanone (14fAc-D). IR (neat, cm−1) 2962,
1
1682, 1458, 1373, 1196, 949; H NMR (CDCl3) δ 7.98–7.96 (m,
2H), 7.59–7.27 (m, 3H), 4.05 (m, 1H), 3.84 (dd, J = 5.7, 8.9 Hz,
1H), 3.56 (dd, J = 5.7, 9.9 Hz, 1H), 1.76–1.65 (m, 1H), 1.60–1.20
(m, 5H), 1.49 (s, 3H), 1.37 (s, 3H), 0.91 (t, J = 6.4 Hz, 3H), 0.82
(t, J = 7.0 Hz, 3H) , 0.60 (t, J = 6.4 Hz, 3H); 13C NMR (CDCl3) δ
198.7, 139.6, 132.5, 128.5, 128.0, 98.9, 71.1, 44.8, 36.0, 30.4,
29.6, 19.6, 18.9, 18.8, 18.4, 13.4; HRMS m/z calcd for
C19H28O3Na [M + Na]+ 327.1936, found 327.1936.
1
1450, 1373, 1196; H NMR (CDCl3) δ 7.95–7.92 (m, 2H), 7.57–
7.43 (m, 3H), 4.34 (dq, J = 3.1 , 6.4 Hz, 1H), 4.02 (dt, J = 3.1,
5.5 Hz, 1H), 3.51 (t, J = 3.1 Hz, 1H), 1.59 (s, 3H), 1.51 (s, 3H),
1.51–1.36 (m, 2H), 1.14 (d, J = 6.4 Hz, 3H), 0.86 (t, J = 7.3 Hz,
3H); 13C NMR (CDCl3) δ 198.7, 139.9, 132.6, 128.5, 127.8, 98.8,
72.7, 66.8, 46.8, 29.7, 16.6, 19.7, 19.0, 10.1; HRMS m/z calcd for
C16H22O3Na [M + Na]+ 285.1467, found 285.1467.
1-[(4RS,5SR,6RS)-4-Ethyl-2,2-dimethyl-6-isopropyl-1,3-di-
oxan-5-yl]ethanone (14gAc-B). IR (neat, cm−1) 2985, 1697,
1465, 1373; 1H NMR (CDCl3) δ 3.85–3.73 (m, 2H), 2.79 (dd, J =
5.7, 8.4 Hz, 1H), 2.25 (s, 3H), 1.46 (s, 3H), 1.33 (s, 3H), 1.64–
1.27 (m, 3H), 0.84 (t, J = 6.9 Hz, 3H), 0.91 (d, J = 6.6 Hz, 3H),
0.86 (d, J = 6.4 Hz, 3H); 13C NMR (CDCl3) δ 210.1, 99.2, 74.0,
[(4RS,5SR,6RS)-4-Isopropyl-2,2,6-trimethyl-1,3-dioxan-5-
yl]phenylmethanone (14dAc-B). IR (neat, cm−1) 2954, 1673,
1
1458, 1373, 1227, 995; H NMR (CDCl3) δ 7.98–7.96 (m, 2H),
7.59–7.44 (m, 3H), 4.05 (dq, J = 6.4, 9.9 Hz, 1H), 3.84 (dd, J =