Publication Date

9-1989

Abstract

Derivatives of 2-methyl-3,4-dihydro-2H,5H-pyrano[3,2-c][1]benzopyran-5-one. (I) Racemic cis-2-hydroxy-4-(2-phenylethyl), C21H20O4, Mr = 336·39, triclinic, P1̄, a = 8·660 (7), b = 14·299 (4), c= 7·320 (4) Å, α = 96·68 (3), β = 99·07(5), γ = 87·554(4)°, V = 888·8(16)Å3, Z = 2, Dx = 1·257 g cm-3, λ(Mo) = 0·71078 Å, μ = 0·807 cm-1, F(000) = 354, T = 294 K, final R = 0·045 for 2844 observations [I ≥ 3δ(I)]. Molecules are hydrogen bonded between hydroxyls and coumarin carbonyl groups in chains along c, with O···O separation of 2·772 (2) Å. The dihydropyran ring is a half-chair, ΔC2 = 0·0057 (8). (II) Spontaneously resolved cis-4-phenyl, C19H16O3, Mr = 292·34, monoclinic, P21, a = 8·267 (6), b = l0·699 (7), c = 9·039 (6) Å, β =113·67(6)°, V = 732·2 (18) Å3, Z = 2, Dx = 1·326 g cm-3, λ(Mo ) = 0·71078 Å, μ = 0·831 cm-1, F(000) = 308, T = 294 K, final R = 0·061 for 2149 observations [I ≥ 3δ(I)]. The dihydropyran ring is in the d,e-diplanar conformation, ΔC2 = 0·0569 (13), and retains the relatively long C—O bond, 1·474 (2) Å, compared to its 2-hydroxy derivatives.

Subjects

Conformation; Molecular structure

Publication Information

Copyright 1989 International Union of Crystallography. The original published version of this article may be found at http://dx.doi.org/10.1107/S0108270189001034.

DOI

10.1107/S0108270189001034

Document Type

Journal Article

Included in

Chemistry Commons

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