Structure of an anti-aldol addition product of benzaldehyde and a pseudoephedrine-derived O-silyl ketene N,O-acetal
Abstract
[4S-(4R*,5R*,8R*,9S*)]-2,2,5,6,8-Pentamethyl-4,9-diphenyl-1,3-dioxa-6-aza-2-silacyclononan-7-one, C_(22)H_(29)NO_3Si, M_r = 383.56, monoclinic, P2_1, a = 6.550 (3), b = 17.318 (6), c = 20.129 (6) Å, β = 98.83 (3)°, V = 2256.2 (14) Å^3, Z = 4, D_x = 1.13 g cm^(-3), λ(Mo Kα) = 0.71073 Å, µ = 1.18 cm^(-1), F(000) = 824, room temperature, R on F = 0.039 for 4305 reflections with F_o^2 > 3σ(F_o^2). The two independent molecules in this structure have nearly the same configuration and geometry, with average Si-C bond distances of 1.842 (3) Å and average Si-O bond distances of 1.636 (7) Å; angles at Si differ from 109.5° by an average of 3.5°. The nine-membered rings are fully extended and the planes of the phenyl groups are approximate perpendicular to the nine-membered ring.
Additional Information
© 1992 International Union of Crystallography. Received 30 September 1991; accepted 18 February 1992. Generous financial support from the National Science Foundation is gratefully acknowledged.Attached Files
Published - hh0589.pdf
Supplemental Material - hh0589.cif
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Additional details
- Eprint ID
- 73574
- Resolver ID
- CaltechAUTHORS:20170120-110900245
- NSF
- Created
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2017-01-21Created from EPrint's datestamp field
- Updated
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2021-11-11Created from EPrint's last_modified field
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- Caltech Division of Chemistry and Chemical Engineering
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- 8513