organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
atoms are disordered over two sites. Excellent agreement is
observed between the geometric features of the O1/P2/O3/
C4±C6 ring of the title compound and those of the structurally
related 2-oxo-1,3,2-dioxaphosphorinanes and their derivatives
[e.g. 2-hydroxy-5-methyl-5-nitro derivatives (Johnson et al.,
1989), several 2-OAr derivatives (Jones et al., 1984), and a
5-hydroxy-2-methoxy derivative (Hamor, 1986)]. The dioxa-
phosphorinane ring in (4) adopts a distorted chair conforma-
tion, with the phenoxy group in an axial position. The dihedral
angles between the least-squares plane through the four
central atoms of the ring (O1, O3, C4 and C6) and the O1/P2/
O3 and C4/C5/C6 planes are 35.86 (10) and 51.84 (15)ꢀ,
respectively. The ¯attening of the ring at the P atom and the
deformation of the chair conformation towards an envelope
have been observed in similar cyclic structures (Jones et al.,
1984). The seemingly energetically unfavourable location of
the large phenoxy substituent in the axial position may be
explained by the anomeric effect that has been noted
previously in a cyclic phosphate (van Nuffel et al., 1980) and is
commonly observed in structures such as that reported here. A
similar location of the P-bonded substituents in the axial
position was also observed in the case of alkyloxy groups, e.g.
methoxy groups in methyl esters (Hamor, 1986) or in bicyclic
organic pyro- and thiopyrophosphates, in which two cyclic
thiophosphates are linked by an O atom (Bukowska-Strzy-
ISSN 0108-2701
5,5-Dimethoxy-2-phenoxy-1,3,2-
dioxaphosphorinane 2-oxide
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Katarzyna Slepokura* and Tadeusz Lis
Faculty of Chemistry, University of Wrocøaw, 14 Joliot-Curie St., 50-383
Wrocøaw, Poland
Correspondence e-mail: slep@wcheto.chem.uni.wroc.pl
Received 26 February 2004
Accepted 15 March 2004
Online 9 April 2004
In the title compound, C11H15O6P, the six-membered dioxa-
phosphorinane ring of the cyclic phosphate triester exists in a
distorted chair conformation, with the phenoxy group in an
axial position. The phenyl ring and both methoxy groups are
in a trans±gauche orientation with respect to the 1,3,2-
dioxaphosphorinane ring. In the phosphate group, a signi®cant
deformation from the ideal tetrahedral shape is observed. The
crystal structure is stabilized by a three-dimensional network
of CÐHÁ Á ÁO interactions.
Ç
zewska & Dobrowolska, 1978, 1980; Jones et al., 1985).
However, when the substituent is ±NMe2, its position is found
to be equatorial (Cameron & Karolak-Wojciechowska, 1977,
and references therein).
The orientation of the aromatic substituent with respect to
the dioxaphosphorinane ring may be described as trans±
gauche (tg), the C11ÐO22ÐP2ÐO1 and C11ÐO22ÐP2ÐO3
torsion angles being 176.70 (12) and 65.65 (13)ꢀ, respectively.
Similarly, the locations of the two methoxy groups are found
to be tg and gt with respect to the dioxaphosphorinane ring
(Table 1).
In the phosphate group, a deformation from the ideal
tetrahedral shape is observed, especially in the O1ÐP2ÐO22
and O21ÐP2ÐO22 bond angles. On the whole, the largest
OÐPÐO angles (Table 1) are those associated with atom O21
Comment
The title compound, (4), the phenyl ester of cyclic di-
hydroxyacetone phosphate dimethyl acetal, is one of the
intermediates in the chemical pathway leading from di-
hydroxyacetone (DHA) to dihydroxyacetone phosphate
(DHAP), as described by Ferroni et al. (1999). The present
paper is the second of a series of crystal structure investiga-
tions of this chemical pathway, which we have undertaken as a
completion of our research on DHAP, its precursors and
Â
analogues (Mazurek & Lis, 1999; Slepokura et al., 2003). The
other compounds, namely DHA in the monomeric and three
dimeric forms, and two complexes of DHA with calcium
chloride and dihydroxyacetone dimethyl acetal, have been
Â
reported elsewhere (Slepokura & Lis, 2004). In general, six-
membered cyclic phosphate esters are present in a number of
biologically important molecules, e.g. cyclic adenosine mono-
phosphate.
Figure 1
The molecular structure and atom-numbering scheme of (4), showing the
disorder of the H atoms at methyl atom C52. Displacement ellipsoids are
drawn at the 40% probability level.
The molecular structure and atom-numbering scheme of (4)
are shown in Fig. 1. In one of the methyl groups (C52), the H
Acta Cryst. (2004). C60, o315±o317
DOI: 10.1107/S0108270104006110
# 2004 International Union of Crystallography o315
Slepokura, Katarzyna
