(2''S,5''R,7''S)-2-[2'-(2''-Methyl-1'',6''-dioxaspiro­[4.5]dec-7''-yl)ethyl­sulfon­yl]-1,3-benzothia­zole

The crystal structure of the title compound, C₁₈H₂₃NO₄S₂, has been investigated in order to establish the relative stereochemistry at the spiro ring junction and the absolute stereochemistry of the mol­ecule. The title compound is a key inter­mediate for the synthesis of the spiro­acetal-containing anti-Helicobacter pylori agent, spiro­laxine methyl ether, for which the absolute stereochemistry has not previously been reported.

Key indicators

• Single-crystal X-ray study
• T = 84 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.022
• wR factor = 0.058
• Data-to-parameter ratio = 16.3

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       1.04
PLAT063_ALERT_3_C Crystal Probably too Large for Beam Size .......       0.68 mm
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?
PLAT143_ALERT_4_C su on c - Axis Small or Missing (x 100000) .....         10 Ang.
PLAT322_ALERT_2_C Check Hybridisation of  S1     in Main Residue .          ?
PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........         25

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           27.08
           From the CIF: _reflns_number_total               3685
           Count of symmetry unique reflns         2180
           Completeness (_total/calc)            169.04%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured      1505
           Fraction of Friedel pairs measured     0.690
           Are heavy atom types Z>Si present        yes

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   6 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   5 ALERT type 4 Improvement, methodology, query or suggestion

---

Computing details

Data collection: SMART (Siemens, 1995); cell refinement: SMART; data reduction: SAINT (Siemens, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Burnett & Johnson, 1996); software used to prepare material for publication: SHELXTL (Siemens, 1995).

(2''S,5''R,7''S)-2-[2'-(2''-Methyl-1'',6''-dioxaspiro[4.5]dec-7''- yl)ethylsulfonyl]-1,3-benzothiazole

Crystal data

C18H23NO4S2	F(000) = 404
Mr = 381.49	Dx = 1.382 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
a = 7.8132 (1) Å	Cell parameters from 8192 reflections
b = 7.3784 (1) Å	θ = 1.3–27.1°
c = 15.8984 (1) Å	µ = 0.31 mm^−1
β = 90.628 (1)°	T = 84 K
V = 916.47 (2) Å^3	Plate, colourless
Z = 2	0.68 × 0.40 × 0.17 mm

Data collection

Siemens SMART CCD area-detector diffractometer	3685 independent reflections
Radiation source: fine-focus sealed tube	3592 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.023
ω scans	θmax = 27.1°, θmin = 1.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −9→9
Tmin = 0.789, Tmax = 0.912	k = −9→9
9314 measured reflections	l = −20→20

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.022	H-atom parameters constrained
wR(F^2) = 0.058	w = 1/[σ^2(Fo^2) + (0.0305P)^2 + 0.1652P] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max = 0.001
3685 reflections	Δρmax = 0.33 e Å^−3
226 parameters	Δρmin = −0.23 e Å^−3
1 restraint	Absolute structure: Flack (1983), with how many Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.02 (4)

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
S1	0.51118 (4)	0.34732 (5)	0.68440 (2)	0.01683 (8)
S2	0.52689 (4)	0.73531 (5)	0.75020 (2)	0.01770 (8)
O1	0.40089 (14)	0.65028 (16)	0.80331 (7)	0.0269 (3)
O2	0.48692 (14)	0.90519 (15)	0.70972 (7)	0.0238 (2)
O6''	0.93092 (12)	1.06997 (13)	0.85808 (6)	0.0151 (2)
O1''	0.78651 (11)	1.34573 (15)	0.87578 (6)	0.01571 (19)
N3	0.67137 (15)	0.60976 (19)	0.60685 (8)	0.0190 (3)
C7a	0.62301 (18)	0.2934 (2)	0.59338 (9)	0.0167 (3)
C7	0.64357 (18)	0.1240 (2)	0.55511 (9)	0.0204 (3)
H7	0.5920	0.0204	0.5765	0.024*
C6	0.74483 (19)	0.1174 (3)	0.48342 (10)	0.0244 (3)
H6	0.7627	0.0068	0.4569	0.029*
C5	0.8206 (2)	0.2750 (3)	0.45044 (10)	0.0268 (4)
H5	0.8862	0.2663	0.4021	0.032*
C4	0.7999 (2)	0.4416 (2)	0.48796 (10)	0.0247 (3)
H4	0.8508	0.5446	0.4657	0.030*
C3a	0.69975 (18)	0.4522 (2)	0.56098 (9)	0.0189 (3)
C2	0.57688 (18)	0.5714 (2)	0.67126 (9)	0.0165 (3)
C1'	0.72290 (18)	0.7541 (2)	0.80758 (9)	0.0185 (3)
H1'A	0.7032	0.8252	0.8579	0.022*
H1'B	0.7587	0.6340	0.8253	0.022*
C2'	0.86923 (17)	0.8423 (2)	0.75767 (9)	0.0193 (3)
H2'A	0.9769	0.7871	0.7747	0.023*
H2'B	0.8518	0.8176	0.6983	0.023*
C7''	0.88128 (17)	1.0461 (2)	0.77062 (9)	0.0157 (3)
H7''	0.7682	1.1004	0.7612	0.019*
C8''	1.01000 (18)	1.1358 (2)	0.71238 (9)	0.0191 (3)
H8''A	0.9710	1.1243	0.6545	0.023*
H8''B	1.1198	1.0753	0.7177	0.023*
C9''	1.03014 (17)	1.3366 (2)	0.73481 (9)	0.0184 (3)
H9''A	0.9239	1.4004	0.7232	0.022*
H9''B	1.1193	1.3904	0.7009	0.022*
C10''	1.07708 (16)	1.3540 (2)	0.82866 (8)	0.0178 (3)
H10A	1.1902	1.3035	0.8385	0.021*
H10B	1.0803	1.4811	0.8441	0.021*
C5''	0.94813 (16)	1.25546 (19)	0.88352 (8)	0.0140 (3)
C2''	0.69744 (16)	1.3459 (2)	0.95576 (8)	0.0169 (3)
H2''	0.6918	1.4707	0.9767	0.020*
C3''	0.80902 (17)	1.2338 (2)	1.01610 (8)	0.0184 (3)
H3''A	0.7722	1.1083	1.0174	0.022*
H3''B	0.8067	1.2830	1.0727	0.022*
C4''	0.98782 (16)	1.2517 (2)	0.97779 (8)	0.0161 (3)
H4''A	1.0437	1.3626	0.9960	0.019*
H4''B	1.0596	1.1491	0.9926	0.019*
C11''	0.51628 (18)	1.2760 (2)	0.94228 (10)	0.0248 (3)
H11A	0.4565	1.3539	0.9035	0.037*
H11B	0.4576	1.2746	0.9950	0.037*
H11C	0.5203	1.1554	0.9197	0.037*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.01558 (15)	0.01636 (17)	0.01859 (16)	−0.00168 (13)	0.00247 (12)	0.00063 (15)
S2	0.01720 (15)	0.01532 (17)	0.02066 (17)	−0.00087 (14)	0.00457 (12)	−0.00010 (14)
O1	0.0272 (6)	0.0220 (6)	0.0317 (6)	−0.0040 (5)	0.0142 (4)	−0.0013 (5)
O2	0.0203 (5)	0.0200 (6)	0.0312 (6)	0.0019 (4)	0.0004 (4)	0.0040 (5)
O6''	0.0166 (5)	0.0123 (5)	0.0165 (5)	0.0007 (4)	−0.0012 (4)	−0.0003 (4)
O1''	0.0129 (4)	0.0161 (5)	0.0182 (4)	0.0032 (4)	0.0012 (3)	0.0024 (4)
N3	0.0175 (6)	0.0223 (7)	0.0173 (6)	−0.0032 (5)	−0.0001 (4)	0.0012 (5)
C7a	0.0119 (6)	0.0213 (7)	0.0169 (6)	−0.0013 (5)	−0.0022 (5)	0.0008 (5)
C7	0.0181 (6)	0.0223 (8)	0.0207 (7)	−0.0017 (6)	−0.0032 (5)	−0.0015 (6)
C6	0.0229 (7)	0.0280 (8)	0.0222 (8)	0.0003 (7)	−0.0029 (6)	−0.0081 (7)
C5	0.0240 (8)	0.0361 (10)	0.0204 (7)	−0.0044 (6)	0.0046 (6)	−0.0058 (7)
C4	0.0233 (8)	0.0300 (9)	0.0210 (7)	−0.0066 (6)	0.0051 (6)	−0.0014 (7)
C3a	0.0158 (7)	0.0234 (8)	0.0174 (7)	−0.0037 (6)	−0.0022 (5)	−0.0006 (6)
C2	0.0153 (6)	0.0151 (7)	0.0192 (6)	−0.0022 (5)	−0.0001 (5)	0.0009 (6)
C1'	0.0237 (7)	0.0145 (7)	0.0174 (6)	−0.0010 (6)	−0.0008 (5)	−0.0008 (6)
C2'	0.0176 (6)	0.0192 (7)	0.0211 (7)	0.0005 (6)	−0.0011 (5)	−0.0030 (7)
C7''	0.0133 (6)	0.0172 (7)	0.0167 (6)	0.0009 (5)	−0.0011 (5)	−0.0011 (6)
C8''	0.0158 (7)	0.0237 (8)	0.0179 (7)	0.0007 (6)	0.0018 (5)	−0.0009 (6)
C9''	0.0148 (6)	0.0202 (7)	0.0202 (6)	−0.0011 (6)	0.0021 (5)	0.0040 (6)
C10''	0.0139 (6)	0.0178 (7)	0.0218 (7)	−0.0023 (6)	0.0007 (5)	0.0009 (6)
C5''	0.0105 (6)	0.0124 (7)	0.0192 (6)	0.0007 (5)	−0.0018 (4)	−0.0009 (6)
C2''	0.0156 (6)	0.0160 (7)	0.0190 (6)	−0.0001 (6)	0.0020 (5)	0.0010 (6)
C3''	0.0191 (6)	0.0190 (7)	0.0172 (6)	0.0027 (6)	0.0007 (5)	0.0009 (6)
C4''	0.0161 (6)	0.0122 (7)	0.0201 (7)	−0.0004 (6)	−0.0024 (5)	−0.0006 (6)
C11''	0.0151 (7)	0.0297 (9)	0.0298 (8)	−0.0036 (6)	0.0015 (6)	0.0048 (7)

Geometric parameters (Å, º)

S1—C7a	1.7446 (15)	C2'—H2'A	0.9700
S1—C2	1.7446 (15)	C2'—H2'B	0.9700
S2—O2	1.4417 (12)	C7''—C8''	1.525 (2)
S2—O1	1.4470 (11)	C7''—H7''	0.9800
S2—C1'	1.7794 (14)	C8''—C9''	1.532 (2)
S2—C2	1.7891 (15)	C8''—H8''A	0.9700
O6''—C5''	1.4330 (17)	C8''—H8''B	0.9700
O6''—C7''	1.4502 (16)	C9''—C10''	1.5380 (19)
O1''—C5''	1.4317 (16)	C9''—H9''A	0.9700
O1''—C2''	1.4562 (15)	C9''—H9''B	0.9700
N3—C2	1.3001 (19)	C10''—C5''	1.5242 (18)
N3—C3a	1.391 (2)	C10''—H10A	0.9700
C7a—C7	1.400 (2)	C10''—H10B	0.9700
C7a—C3a	1.416 (2)	C5''—C4''	1.5275 (18)
C7—C6	1.395 (2)	C2''—C11''	1.5194 (19)
C7—H7	0.9300	C2''—C3''	1.5317 (19)
C6—C5	1.409 (2)	C2''—H2''	0.9800
C6—H6	0.9300	C3''—C4''	1.5358 (18)
C5—C4	1.376 (2)	C3''—H3''A	0.9700
C5—H5	0.9300	C3''—H3''B	0.9700
C4—C3a	1.409 (2)	C4''—H4''A	0.9700
C4—H4	0.9300	C4''—H4''B	0.9700
C1'—C2'	1.543 (2)	C11''—H11A	0.9600
C1'—H1'A	0.9700	C11''—H11B	0.9600
C1'—H1'B	0.9700	C11''—H11C	0.9600
C2'—C7''	1.521 (2)
C7a—S1—C2	88.05 (7)	C7''—C8''—C9''	110.18 (12)
O2—S2—O1	119.47 (7)	C7''—C8''—H8''A	109.6
O2—S2—C1'	110.01 (7)	C9''—C8''—H8''A	109.6
O1—S2—C1'	108.78 (7)	C7''—C8''—H8''B	109.6
O2—S2—C2	108.81 (7)	C9''—C8''—H8''B	109.6
O1—S2—C2	105.75 (7)	H8''A—C8''—H8''B	108.1
C1'—S2—C2	102.65 (7)	C8''—C9''—C10''	109.21 (12)
C5''—O6''—C7''	114.19 (10)	C8''—C9''—H9''A	109.8
C5''—O1''—C2''	110.79 (10)	C10''—C9''—H9''A	109.8
C2—N3—C3a	109.04 (13)	C8''—C9''—H9''B	109.8
C7—C7a—C3a	121.99 (13)	C10''—C9''—H9''B	109.8
C7—C7a—S1	128.66 (12)	H9''A—C9''—H9''B	108.3
C3a—C7a—S1	109.34 (11)	C5''—C10''—C9''	111.31 (11)
C6—C7—C7a	117.03 (15)	C5''—C10''—H10A	109.4
C6—C7—H7	121.5	C9''—C10''—H10A	109.4
C7a—C7—H7	121.5	C5''—C10''—H10B	109.4
C7—C6—C5	121.32 (16)	C9''—C10''—H10B	109.4
C7—C6—H6	119.3	H10A—C10''—H10B	108.0
C5—C6—H6	119.3	O1''—C5''—O6''	109.88 (10)
C4—C5—C6	121.59 (14)	O1''—C5''—C10''	108.48 (11)
C4—C5—H5	119.2	O6''—C5''—C10''	110.76 (11)
C6—C5—H5	119.2	O1''—C5''—C4''	105.20 (10)
C5—C4—C3a	118.41 (15)	O6''—C5''—C4''	106.08 (11)
C5—C4—H4	120.8	C10''—C5''—C4''	116.22 (11)
C3a—C4—H4	120.8	O1''—C2''—C11''	109.26 (11)
N3—C3a—C4	124.85 (15)	O1''—C2''—C3''	105.79 (10)
N3—C3a—C7a	115.48 (13)	C11''—C2''—C3''	115.34 (13)
C4—C3a—C7a	119.66 (15)	O1''—C2''—H2''	108.8
N3—C2—S1	118.09 (11)	C11''—C2''—H2''	108.8
N3—C2—S2	122.39 (11)	C3''—C2''—H2''	108.8
S1—C2—S2	119.33 (8)	C2''—C3''—C4''	102.66 (11)
C2'—C1'—S2	114.06 (10)	C2''—C3''—H3''A	111.2
C2'—C1'—H1'A	108.7	C4''—C3''—H3''A	111.2
S2—C1'—H1'A	108.7	C2''—C3''—H3''B	111.2
C2'—C1'—H1'B	108.7	C4''—C3''—H3''B	111.2
S2—C1'—H1'B	108.7	H3''A—C3''—H3''B	109.1
H1'A—C1'—H1'B	107.6	C5''—C4''—C3''	102.41 (10)
C7''—C2'—C1'	113.11 (12)	C5''—C4''—H4''A	111.3
C7''—C2'—H2'A	109.0	C3''—C4''—H4''A	111.3
C1'—C2'—H2'A	109.0	C5''—C4''—H4''B	111.3
C7''—C2'—H2'B	109.0	C3''—C4''—H4''B	111.3
C1'—C2'—H2'B	109.0	H4''A—C4''—H4''B	109.2
H2'A—C2'—H2'B	107.8	C2''—C11''—H11A	109.5
O6''—C7''—C2'	105.39 (11)	C2''—C11''—H11B	109.5
O6''—C7''—C8''	110.99 (11)	H11A—C11''—H11B	109.5
C2'—C7''—C8''	112.77 (12)	C2''—C11''—H11C	109.5
O6''—C7''—H7''	109.2	H11A—C11''—H11C	109.5
C2'—C7''—H7''	109.2	H11B—C11''—H11C	109.5
C8''—C7''—H7''	109.2