Molecules 1997, 2, M33

tert-Butyl-3-methoxy-5,5-dimethyl-7-hydroxy-8-trimethylsilyl-9-decenoate

Douglas A. Smith

The DASGroup, Inc., 1732 Lyter Drive, 2nd Floor, Johnstown, Pennsylvania 15905-1206, USA, and Department of Chemistry, University of Toledo, Toledo, Ohio 43606-3390, USA. Tel. +1 814 255 7859, Fax +1 814 255 3517, Email [email protected]

Received: 29 September 1997 / Published: 31 October 1997



Scheme

The crude aldehyde, tert-butyl-3-methoxy-5,5-dimethyl-7-oxo-heptanoate [1] was treated with pinacol E-1-trimethylsilyl-1-propene-3-boronate [2] in petroleum ether at room temperature to provide a 50% yield of the diastereomeric boronic esters, which were simultaneously cleaved to the alcohols and readily separated by flash chromatography.

Following the procedure of Tsai and Matteson [2] the crude aldehyde and pinacol E-1- trimethylsilyl-1-propene-3-boronate were stirred at room temperature in ether for 40 hours and then concentrated. The title compound was obtained as a colorless oil as an 1 : 1 mixture of separable (flash chromatography, 10 : 1 pet ether : ether) diastereoisomers in 50% yield.

Less polar diastereoisomer.

1H NMR (CDCl3): d: 5.83 (dt, J = 17.1, 10.5Hz, 1H), 4.93 (dd, J = 10.5, 2.3Hz, 1H), 4.83 (dd, J = 17.1, 2.3Hz, 1H), 4.0 (m, 1H), 3.68 (m, 1H), 3.33 (s, 3H), 2.54 (dd, J = 14.8, 4.4Hz, 1H), 2.17 (dd, J = 14.8, 8.4Hz, 1H), 1.96 (dd, J = 15.2, 10.2Hz, 1H), 1.7 (dd, J = 14.9, 10.2Hz, 1H), 1.42 (s, 10H), 1.2 - 1.0 (m, 3H), 0.94 (s, 3H), 0.91 (s, 3H), 0.01 (s, 9H).

IR (CDCl3): 3450, 2965, 1720, 1460, 1370, 1255, 1060, 880.

MS (m/e): 316, 315, 284, 283, 226, 203, 194, 171, 157, 143, 127 (100).

HRMS: calc. for C16H32O4Si (M - C4H8): 316.2070; found: 316.2070.

More polar diastereoisomer.

1H NMR (CDCl3): d: 5.81 (dt, 17.1, 10.5Hz, 1H), 5.00 (dd, J = 10.5, 2.2Hz, 1H), 4.88 (dd, J = 17.1, 2.2Hz, 1H), 3.98 (m, 1H), 3.64 (m, 1H), 3.26 (s, 3H), 2.53 (dd, J = 15.0, 4.9Hz, 1H), 2.19 (dd, J = 15.0, 7.9Hz, 1H), 1.89 (d, J = 5.2Hz, 1H), 1.7 - 1.2 (m, 4H), 1.42 (s, 9H), 1.15 - 1.05 (m, 1H), 0.96 (s, 3H), 0.94 (s, 3H), 0.02 (s, 9H).

IR (CDCl3): 3400, 2950, 1715, 1460, 1365, 880.

MS (m/e): 316, 315, 284, 283, 226, 203, 194, 171, 157, 143, 127 (100).

Anal. calc. for C16H32O4Si (M - C4H8): 316.2070; found: 316.2070.


References and Notes
  1. Smith, D. tert-Butyl-3-methoxy-5,5-dimethyl-7-oxo-heptanoate, Molecules 1997, 2, M32.
  2. Tsai, D. J. S.; Matteson, D. S., Tetrahedron Lett. 1981, 22, 2751.

Sample Availability: No sample available.

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