[4R*,5R*,6S*]-1,7-Dioxaspiro[5.5]undec-4,5-diyl Diacetate

Molecules 1997, 2, M21

**[4R,5R,6S*]-1,7-Dioxaspiro[5.5]undec-4,5-diyl Diacetate**

Margaret A. Brimble* and Andrew D. Johnston

Division of Organic Chemistry, School of Chemistry F11, The University of Sydney, N.S.W 2006, Australia. phone +61-2-9351-2750, fax +61-2-9351-6650, e-mail [email protected], http://www.chem.usyd.edu.au/~brimble

Received: 18 June 1997 / Published: 20 June 1997

To a solution of [4R*,5R*,6S*]-1,7-dioxaspiro[5.5]undecane-4,5-diol (1) (50 mg, 0.27 mmol) in dichloromethane (10 ml) was added triethylamine (100 mg, 0.99 mmol), acetic anhydride (67 mg, 0.66 mmol) and 4-dimethylaminopyridine (3 mg). The reaction mixture allowed to stand at room temperature for 1 h, then quenched with water (2.0 ml), extracted with dichloromethane (2x 50 ml) and dried over sodium sulphate. Removal of the solvent under reduced pressure gave a pale yellow oil, that was purified by flash chromatography using hexane-ethyl acetate (2:1) as eluent to afford [4R*,5R*,6S*]-1,7-dioxaspiro[5.5]undec-4,5-diyl diacetate (2) (69 mg, 94%) as a colourless oil.

High Res. MS calc. for C₁₃H₂₀O₆M⁺H (CI, NH₃) 273.1338, found: M⁺ 273.1337.

IR (Nujol) cm^-1 1731 [s, C=O (ester)], 1080 (s, C-O).

¹H-NMR (200 MHz, CDCl₃) 1.39-1.82 (8H, m, 4-CH₂, 9-CH₂, 10-CH₂, and 11-CH₂), 2.07 (3H, s, Ac), 2.09 (3H, s, Ac), 3.53-3.82 (4H, m, 2-CH₂, and 8-CH₂ ), 3.94 (1H, ddd, J _2ax,2eq11.3, _2ax,3ax 11.3, and _2ax,3eq 3.0 Hz, 2ax-H), 4.81-4.85 (2H, m, 4-H and 5-H).

¹³C-NMR (50 MHz, CDCl₃) 17.6, 24.6 (CH₂, C-9 and C-10), 20.8, 21.1 (CH₃, 2x Ac), 26.3 (CH₂, C-3), 29.3 (CH₂, C-11), 55.9 (CH₂, C-2), 60.8 (CH₂, C-8), 67.9 (CH, C-4), 70.0 (CH, C-5), 96.1 (quat, C-6), 170.1, 171.0 (quat, 2x C=O).

CI-MS 273 (M⁺H, 20%), 213 (100), 153 (30), 101 (5).

Acknowledgment: The authors gratefully acknowledge financial support from the Australian Research Council and The University of Sydney.

Sample Availability: No sample available.