(4R,2'R,3'R,5'R)-3-[3,5-Bis(tert-butyldimethylsilyloxy)-1-oxo- 2-(phenylmethoxy)hexyl]-4-(phenylmethyl)-2-oxazolidinone

Margaret A. Brimble* and Josephine S. O. Park

School of Chemistry, University of Sydney, Eastern Ave, Camperdown, NSW 2006, Australia. Fax: (+61 3) 9351 3329; E-mail: [email protected]

Received: 20 January 2000 / Accepted: 2 February 2000 / Published: 23 February 2000

To a solution of alcohol 1 (225 mg, 0.43 mmol) [1] in dry N,N-dimethylformamide (0.9 ml) at 0°C under an atmosphere of nitrogen was added imidazole (72 mg, 1.1 mmol) and tert-butyldimethylsilyl chloride (67 mg, 0.45 mmol). The resultant solution was allowed to reach room temperature and stirred overnight. The reaction mixture was poured into ether (17 ml), washed with water (3 x 4 ml), brine (4 ml) then dried over sodium sulfate. Removal of the solvent at reduced pressure afforded a pale yellow oil that was purified by flash chromatography using light petroleum-ethyl acetate (4:1) as eluent to give the title compound 2 (246 mg, 89%) as a colourless oil.

[a]_D -41.37 (c 0.614, CHCl₃).

IR (cm^-1, neat): 2956-2856s, 1789s, 1709s, 1386, 1110.

¹H NMR (400 MHz, CDCl₃): 0.01, 0.02, 0.06, 0.09 (12H, s, 2 x SiMe₂), 0.84, 0.88 (18H, s, 2 x Bu^t), 1.13 (3H, d, J_6',5' 6.0 Hz, H6'), 1.71-1.77 (1H, m, H4'^A), 1.87-2.04 (1H, m, H4'^B), 2.55 (1H, dd, J_gem 13.4 and J 9.9 Hz, CHCH^APh), 3.15 (1H, dd, J_gem 13.4 and J 3.2 Hz, CHCH^BPh), 4.06-4.15 (4H, m, H5, H3', H5'), 4.55-4.60 (1H, m, H4), 4.58 (1H, d, J_gem 11.5 Hz, OCH^APh), 4.64 (1H, d, J_gem 11.5 Hz, OCH^BPh), 5.83 (1H, d, J_2',3' 6.6 Hz, H2'), 7.19-7.41 (10H, m, Ph).

¹³C NMR (100 MHz, CDCl₃): -4.8, -4.7, -4.6, -4.5 (CH₃, 2 x SiMe₂), 17.8, 18.0 (quat., 2 x CMe₃), 24.3 (CH₃, C6'), 25.7, 25.9 (CH₃, 2 x CMe₃), 37.7 (CH₂, CHCH₂Ph), 45.5 (CH₂, C4'), 55.6 (CH, C4), 65.6 (CH, C5'), 66.1 (CH₂, C5), 70.8 (CH, C3'), 73.2 (CH₂, OCH₂Ph), 80.7 (CH, C2'), 127.3, 127.9, 128.3, 128.4, 128.9, 129.4 [CH, 2 x Ph (last 4 peaks coincidental)], 135.2 (quat., CHCH₂Ph), 137.5 (quat., OCH₂Ph), 153.0 (quat., C2), 172.1 (quat., C1').

CI-MS (LSIMS, NBA matrix): 642 (MH⁺, 3%), 584 (M-C₄H₁₀, 13), 510 (M-C₆H₁₆OSi, 9), 418 (10), 286 (14), 215 (10) and 159 (C₈H₁₉OSi, 100).

Anal. calc. for C₃₅H₅₅NO₆Si₂ M⁺ (EI), 641.3568; found M⁺, 641.3561.

References

1.	Brimble, M. A.; Park, J. S. O. J. Chem. Soc. Perkin Trans. I 2000, 697-709.

Sample availability: available from the authors.

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