1182 J . Org. Chem., Vol. 62, No. 4, 1997
Notes
matography of the concentrated mother liquor (elution with
5-12% methanol-chloroform) yielded an additional 1.20 g of a
mixture of 1 and its 6-oxa regioisomer in the ratio of 5:2, as
determined by NMR integration.
(m, 1 H), 3.74 (m, 2 H), 3.55 (br d, J ) 8.0 Hz, 1 H), 3.15 (m, 1
H), 0.93 (s, 3 H), 0.90 (d, J ) 6.6 Hz, 3 H), 0.85 (d, J ) 6.5 Hz,
3 H), 0.72 (s, 3 H); 13C-NMR (100 MHz, CDCl3-CD3OD) δ 177.3
(C), 74.2 (CH), 72.6 (CH), 70.5 (CH2), 67.8 (two CH), 58.0 (CH),
52.1 (CH), 51.2 (CH), 42.3 (C), 41.1 (CH2), 40.9 (CH), 40.2 (CH),
39.5 (CH2), 39.0 (CH), 38.9 (CH), 38.1 (C), 36.8 (CH), 31.1 (CH2),
30.8 (two CH2), 27.4 (CH2), 26.5 (two CH2), 26.4 (CH2), 24.6
(CH2), 22.1 (CH2), 15.3 (CH3), 11.7 (CH3), 11.6 (CH3), 9.9 (CH3);
mass spectrum of the 2,3,22,23-tetraacetate,22 m/z (relative
intensity, %) 688 (0.3), 568 (8), 506 (91), 463 (96), 404 (60), 361
(75), 123 (100). Anal. Calcd for C31H52O6: C, 71.50; H, 10.07.
Found: C, 71.16; H, 10.14.
(2R,3S,5r,22R,23R,24S)-24-Cycloh exyl-6,6-(eth ylen edioxy)-
2,3-(isop r op ylid en ed ioxy)-26,27-d in or ch olest a n e-22,23-
d iol (9). The procedure for the preparation of diol 6 was
followed, employing cyclohexylmagnesium chloride instead of the
isopropyl derivative. Flash chromatography (elution with 25-
60% ether-hexanes) afforded 81% of recovered erythro-epoxy
alcohol 5b and 73% (based on the threo-epoxide 5a ) of the 22,23-
diol 9 as a colorless oil: IR (KBr) 3510, 3458, 1240, 1217, 1083,
1
1051, 972, 753 cm-1; H-NMR (200 MHz) δ 4.27 (m, 1 H), 4.10
(2R,3S,5r,22R,23R,24S)-24-n -Dod ecyl-2,3,22,23-tetr a h y-
dr oxy-B-h om o-26,27-din or -7-oxach olestan -6-on e (12). Com-
pound 11 was treated with triflouroperoxyacetic acid as in the
procedure for the preparation of 1. Flash chromatography
(elution with 10-15% isopropyl alcohol-chloroform) provided
86% of a mixture of 12 and its 6-oxa regioisomer in the ratio of
9:1 (NMR integration). Recrystallization from methanol afforded
67% of pure 12: mp 208-211 °C; IR (KBr) 3440, 1695, 1187,
1062, 1044, 981 cm-1; 1H-NMR (400 MHz) δ 4.09 (m, 2 H), 4.03
(m, 1 H), 3.74 (m, 1 H), 3.57 (br s, 2 H), 3.13 (dd, J ) 12.1, 4.1
Hz, 1 H), 0.93 (s, 3 H), 0.91 (d, J ) 6.6 Hz, 3 H), 0.90 (t, J ) 7.0
Hz, 3 H), 0.84 (d, J ) 6.8 Hz, 3 H), 0.72 (s, 3 H); 13C NMR (100
MHz, CDCl3-CD3OD) δ 177.3 (C), 74.8 (CH), 73.9 (CH), 70.5
(CH2), 67.8 (two CH), 58.0 (CH), 52.1 (CH), 51.2 (CH), 42.3 (C),
41.1 (CH2), 40.9 (CH), 39.5 (CH2), 39.0 (CH), 38.1 (C), 37.0 (CH),
34.3 (CH2), 33.8 (CH), 31.8 (CH2), 31.1 (CH2), 29.8 (CH2), 29.6
(five CH2), 29.2 (CH2), 27.4 (CH2), 27.2 (CH2), 24.6 (CH2), 22.6
(CH2), 22.1 (CH2), 15.3 (CH3), 14.0 (CH3), 12.5 (CH3), 11.8 (CH3),
11.6 (CH3); mass spectrum of the 2,3,22,23-tetraacetate,22 m/z
(relative intensity, %) 774 (0.6), 654 (13), 506 (69), 463 (91), 404
(58), 361 (62), 43 (100). Anal. Calcd for C37H66O6: C, 73.22; H,
10.96. Found: C, 73.00; H, 10.70.
(m, 1 H), 3.92 (m, 3 H), 3.73 (m, 2 H), 3.55 (m, 1 H), 1.47 (s, 3
H), 1.32 (s, 3 H), 0.88 (d, J ) 5.8 Hz, 3 H), 0.83 (d, J ) 6.0 Hz,
3 H), 0.83 (s, 3 H), 0.67 (s, 3 H); 13C-NMR (100 MHz) δ 109.7
(C), 107.5 (C), 74.7 (CH), 72.9 (CH), 72.8 (CH), 72.4 (CH), 65.5
(CH2), 64.1 (CH2), 55.8 (CH), 52.9 (CH), 52.3 (CH), 45.4 (CH),
42.6 (CH2), 42.3 (C), 40.9 (CH2), 40.4 (CH), 39.7 (CH2), 38.8 (CH),
38.0 (C), 36.8 (CH), 32.9 (CH), 31.0 (CH2), 30.9 (CH2), 28.6 (CH3),
27.7 (CH2), 26.6 (CH2), 26.6 (CH3), 24.0 (CH2), 21.9 (CH2), 20.7
(CH2), 13.4 (CH3), 11.9 (2 CH3), 10.0 (CH3); mass spectrum, m/z
(relative intensity %) 588 (2), 573 (8), 446 (16), 431 (60), 235
(100). Exact mass calcd for
588.4371.
C36H60O6: 588.4390. Found:
(2R,3S,5r,22R,23R,24S)-24-n -Dodecyl-6,6-(eth ylen edioxy)-
2,3-(isop r op ylid en ed ioxy)-26,27-d in or ch olest a n e-22,23-
d iol (10). The procedure for the preparation of diol 6 was
followed, except that n-dodecylmagnesium chloride was em-
ployed instead of the isopropyl derivative, and the reaction was
performed at -40 °C. Flash chromatography (elution with 25-
60% ether-hexanes) afforded 88% of recovered erythro-epoxy
alcohol 5b and 69% (based on the threo-epoxide 5a ) of the 22,23-
diol 10 as a colorless oil: IR (KBr) 3409, 1238, 1218, 1082, 1051
cm-1 1H-NMR (400 MHz) δ 4.29 (m, 1 H), 4.10 (m, 1 H), 3.92
;
Ack n ow led gm en t. We thank the Natural Sciences
and Engineering Research Council of Canada (NSERC)
for financial support. D.L.B. gratefully acknowledges
receipt of an NSERC Postgraduate Scholarship, an
Honorary Killam Fellowship and a Ralph Steinhauer
Award. We thank Dr. Prakash Patil (Beak Consultants
Ltd.) for some helpful discussions.
(m, 3 H), 3.75 (m, 1 H), 3.55 (br s, 2 H), 1.49 (s, 3 H), 1.32 (s, 3
H), 0.91 (d, J ) 5.6 Hz, 3 H), 0.89 (d, J ) 6.1 Hz, 3 H), 0.85 (t,
J ) 7.9 Hz, 3 H), 0.84 (s, 3 H), 0.69 (s, 3 H); 13C-NMR (100 MHz)
δ 109.7 (C), 107.6 (C), 75.0 (CH), 74.4 (CH), 72.9 (CH), 72.8 (CH),
65.5 (CH2), 64.1 (CH2), 55.8 (CH), 53.0 (CH), 52.3 (CH), 45.4
(CH), 42.6 (CH2), 42.3 (C), 40.9 (CH2), 39.7 (CH2), 38.0 (C), 37.0
(CH), 34.4 (CH2), 33.8 (CH), 32.9 (CH), 31.9 (CH2), 29.8 (CH2),
29.6 (five CH2), 29.3 (CH2), 28.6 (CH3), 27.7 (CH2), 27.3 (CH2),
26.5 (CH3), 24.0 (CH2), 22.6 (CH2), 21.9 (CH2), 20.7 (CH2), 14.1
(CH3), 13.4 (CH3), 12.7 (CH3), 12.0 (CH3), 11.9 (CH3); mass
spectrum, m/z (relative intensity %) 674 (2), 659 (6), 431 (29),
235 (85), 58 (100). Exact mass calcd for C42H74O6: 674.5485.
Found: 674.5521.
(2R,3S,5r,22R,23R,24S)-24-Cycloh exyl-2,3,22,23-tetr a h y-
dr oxy-B-h om o-26,27-din or -7-oxach olestan -6-on e (11). Com-
pound 9 was treated with triflouroperoxyacetic acid as in the
procedure for the preparation of 1. Flash chromatography
(elution with 10-15% isopropyl alcohol-chloroform) provided
69% of a mixture of 11 and its 6-oxa regioisomer in the ratio of
9:1 (NMR integration). Recrystallization from methanol afforded
51% of pure 11: mp 277-280 °C; IR (KBr) 3452, 1697, 1185,
1066, 1027, 979 cm-1; 1H-NMR (400 MHz) δ 4.09 (m, 2 H), 4.03
Su p p or tin g In for m a tion Ava ila ble: 1H-NMR and 13C-
NMR spectra of brassinolide (1) and of the side-chain ana-
logues 9-12 (10 pages). This material is contained in libraries
on microfiche, immediately follows this article in the microform
version of the journal, and can be ordered from the ACS; see
any current masthead page for ordering information.
J O961854Y
(22) The electron impact mass spectra of the tetrols 11 and 12 did
not show their molecular ions. The mass spectra are therefore reported
for the corresponding tetraacetates, which were prepared by treating
11 and 12 with acetic anhydride and 4-(dimethylamino)pyridine in
pyridine for 4 h at room temperature.