2-O-(4,4′-Dimethyl­benzhydr­yl)-L-erythronolactone

The high regioselectivity of the SnCl₂-catalyzed reaction of diaryl­diazo­methanes with vicinal diols was demonstrated by the reaction of diazo­[bis­(4-methyl­phen­yl)]methane with L-erythronolactone. The major product was unequivocally established by X-ray crystallographic analysis to be the title compound, C₁₉H₂₀O₄. The absolute configuration was determined by the use of L-erythronolactone as the starting material. The crystal structure contains alternating O—H...O hydrogen-bonded chains of mol­ecules lying perpendicular to the bc plane.

Key indicators

• Single-crystal X-ray study
• T = 150 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.059
• wR factor = 0.171
• Data-to-parameter ratio = 10.2

checkCIF/PLATON results

No syntax errors found



Alert level C
ABSTM02_ALERT_3_C  The ratio of expected to reported Tmax/Tmin(RR') is < 0.90
            Tmin and Tmax reported:      0.840     0.990
            Tmin(prime) and Tmax expected:      0.957     0.991
            RR(prime) =      0.879
            Please check that your absorption correction is appropriate.
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.97
PLAT061_ALERT_3_C Tmax/Tmin Range Test RR' too Large .............       0.88
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?
PLAT340_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          6

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           27.50
           From the CIF: _reflns_number_total               2112
           Count of symmetry unique reflns         2191
           Completeness (_total/calc)             96.39%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present         no
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C17    = .          S
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C21    = .          S

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

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


checkCIF publication errors

Alert level A
PUBL024_ALERT_1_A The number of authors is greater than 5.
              Please specify the role of each of the co-authors
              for your paper.

Author Response: Petursson, Sigthor - Preparative Group Leader (Akureyi); Jenkinson, Sarah F. - Post Doc chemist and crystallographer; Booth, Kathrine V. - trainee crystallographer; Weymouth-Wilson, Alexander C. - industrial supervisor; Watkin, David J. - senior crystallographer; Fleet, George W. J. - Preparative Group Leader (Oxford); Best, Dan - preparative chemist.

   1 ALERT level A = Data missing that is essential or data in wrong format
   0 ALERT level G = General alerts. Data that may be required is missing

---

S1. Comment

Carbohydrates provide excellent starting materials for the synthesis of small chiral molecules (Collins & Ferrier, 1995). They are relatively inexpensive and provide an almost boundless pool of chiral building blocks (Draths et al., 1992). L-Erythronolactone 1, readily available from D-arabinose (Humphlett, 1967), is an underused carbohydrate synthon due to the difficulty in differentiating between the two secondary hydroxyl groups.

Diazodiphenylmethane has been found to be a useful protecting group in the synthesis of methyl 2,3,6-tri-O-methyl-[α]-D-glucopyranoside and kojibiose octa-acetate (Jackson et al., 1982), and monoalkylations of vicinal diols have been achieved with this reagent and other diaryldiazoalkanes in the presence of catalytic amounts of tin(II) chloride with high regioselectivities (Petursson & Webber, 1982; Petursson, 2001, 2003).

The reaction of L-erythronolactone with diazo[bis(4-methylphenyl)]methane and a catalytic amount of tin(II) chloride in 1,2-dimethoxyethane gave a 5:1 mixture of mono-protected lactones 2 and 3 (Fig. 1). The crystal structure has firmly established that the major product is the title compound, 2 (Fig. 2). The crystal structure consists of alternating hydrogen-bonded chains of molecules lying perpendicular to the bc plane (Fig. 3).

Related literature

For related literature, see: Humphlett (1967); Jackson et al. (1982); Petursson & Webber (1982); Petursson (2001, 2003); Collins & Ferrier (1995); Draths et al. (1992); Görbitz (1999).

S2. Experimental

2-O-(4,4'-Dimethylbenzhydryl)-L-erythronolactone was recrystallized by vapour diffusion of hexane into ethyl acetate: m.p. 425–427 K; [α]_D²¹ -51.7 (c, 1.08 in chloroform).

S3. Refinement

In the absence of significant anomalous scattering, Friedel pairs were merged and the absolute configuration was assigned on the basis of the starting material.

The relatively large ratio of minimum to maximum corrections applied in the multiscan process (1:1.18) reflect changes in the illuminated volume of the crystal. Changes in illuminated volume were kept to a minimum, and were taken into account (Görbitz, 1999) by the multi-scan inter-frame scaling (DENZO/SCALEPACK, Otwinowski & Minor, 1997).

The H atoms were all located in a difference map, but those attached to carbon atoms were repositioned geometrically. The H atoms were initially refined with soft restraints on the bond lengths and angles to regularize their geometry (C—H in the range 0.93–0.98 and O—H 0.82 Å) and U_iso(H) (in the range 1.2–1.5 times U_eq of the parent atom), after which the positions were refined with riding constraints.

Computing details

Data collection: COLLECT (Nonius, 2001); cell refinement: DENZO/SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO/SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003); molecular graphics: CAMERON (Watkin et al., 1996); software used to prepare material for publication: CRYSTALS (Betteridge et al., 2003).

Figures

	Fig. 1. The reaction leading to the title compound.
	Fig. 2. The molecular structure with displacement ellipsoids drawn at the 50% probability level. H atoms are shown as spheres of arbitrary radius.
	Fig. 3. The crystal structure consists of alternate layers of hydrogen-bonded chains of molecules lying perpendicular to the bc plane.

2-O-(4,4'-Dimethylbenzhydryl)-L-erythronolactone

Crystal data

C19H20O4	Dx = 1.268 Mg m^−3
Mr = 312.37	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P212121	Cell parameters from 1832 reflections
a = 6.1276 (2) Å	θ = 5–27°
b = 8.8248 (3) Å	µ = 0.09 mm^−1
c = 30.2629 (10) Å	T = 150 K
V = 1636.46 (9) Å^3	Needle, colourless
Z = 4	0.50 × 0.10 × 0.10 mm
F(000) = 664

Data collection

Nonius KappaCCD diffractometer	1323 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.086
ω scans	θmax = 27.5°, θmin = 5.2°
Absorption correction: multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997)	h = −7→7
Tmin = 0.84, Tmax = 0.99	k = −11→11
7163 measured reflections	l = −37→38
2112 independent reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.059	H-atom parameters constrained
wR(F^2) = 0.171	w = 1/[σ^2(F^2) + (0.1P)^2] , where P = (max(Fo^2,0) + 2Fc^2)/3
S = 0.93	(Δ/σ)max = 0.000110
2112 reflections	Δρmax = 0.39 e Å^−3
208 parameters	Δρmin = −0.39 e Å^−3
0 restraints

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

	x	y	z	Uiso*/Ueq
O1	0.5621 (5)	0.7497 (3)	0.16641 (6)	0.0368
C2	0.5141 (7)	0.6595 (4)	0.12785 (10)	0.0360
C3	0.6524 (7)	0.5171 (4)	0.12688 (10)	0.0328
C4	0.8599 (8)	0.5137 (4)	0.14619 (10)	0.0381
C5	0.9777 (8)	0.3806 (5)	0.14738 (11)	0.0406
C6	0.8997 (8)	0.2478 (5)	0.12948 (11)	0.0423
C7	0.6980 (8)	0.2533 (5)	0.10875 (12)	0.0461
C8	0.5765 (8)	0.3839 (4)	0.10784 (10)	0.0380
C9	1.0239 (11)	0.1014 (5)	0.13336 (14)	0.0682
C10	0.5396 (7)	0.7615 (4)	0.08805 (10)	0.0360
C11	0.7307 (8)	0.7685 (5)	0.06273 (12)	0.0447
C12	0.7456 (9)	0.8691 (5)	0.02763 (12)	0.0476
C13	0.5725 (8)	0.9631 (5)	0.01651 (11)	0.0424
C14	0.3827 (8)	0.9546 (5)	0.04116 (11)	0.0446
C15	0.3677 (8)	0.8529 (5)	0.07647 (11)	0.0422
C16	0.5911 (10)	1.0723 (6)	−0.02186 (13)	0.0653
C17	0.4910 (7)	0.6830 (4)	0.20603 (10)	0.0354
C18	0.2803 (7)	0.7510 (5)	0.22240 (11)	0.0372
O19	0.2760 (5)	0.7464 (3)	0.26658 (7)	0.0452
C20	0.4842 (8)	0.6878 (5)	0.28307 (11)	0.0488
C21	0.6449 (7)	0.7073 (5)	0.24494 (12)	0.0392
O22	0.7273 (5)	0.8564 (3)	0.24595 (8)	0.0425
O23	0.1313 (5)	0.8012 (3)	0.20124 (8)	0.0481
H21	0.3591	0.6243	0.1266	0.0485*
H41	0.9144	0.6059	0.1587	0.0493*
H51	1.1210	0.3779	0.1629	0.0504*
H71	0.6433	0.1650	0.0941	0.0580*
H81	0.4389	0.3839	0.0941	0.0458*
H91	0.9516	0.0236	0.1167	0.1067*
H92	1.0233	0.0731	0.1638	0.1061*
H93	1.1723	0.1170	0.1245	0.1064*
H111	0.8500	0.7011	0.0690	0.0541*
H121	0.8764	0.8725	0.0102	0.0612*
H141	0.2599	1.0180	0.0336	0.0573*
H151	0.2375	0.8467	0.0924	0.0525*
H161	0.4540	1.1194	−0.0262	0.1014*
H162	0.7021	1.1475	−0.0148	0.1017*
H163	0.6272	1.0160	−0.0482	0.1013*
H171	0.4638	0.5726	0.2016	0.0455*
H201	0.5259	0.7483	0.3091	0.0600*
H202	0.4712	0.5830	0.2925	0.0609*
H211	0.7611	0.6306	0.2456	0.0579*
H26	0.8375	0.8918	0.2326	0.0714*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0501 (18)	0.0382 (13)	0.0222 (11)	−0.0038 (15)	0.0037 (11)	−0.0011 (10)
C2	0.036 (2)	0.045 (2)	0.0275 (16)	−0.002 (2)	−0.0028 (17)	−0.0065 (15)
C3	0.035 (2)	0.0386 (19)	0.0252 (16)	−0.0005 (19)	−0.0009 (16)	0.0027 (14)
C4	0.041 (3)	0.039 (2)	0.0348 (18)	−0.001 (2)	−0.0005 (18)	−0.0061 (15)
C5	0.040 (3)	0.049 (2)	0.0331 (18)	0.006 (2)	−0.0016 (18)	0.0042 (16)
C6	0.056 (3)	0.038 (2)	0.0336 (18)	0.008 (2)	0.0120 (19)	0.0021 (17)
C7	0.059 (3)	0.042 (2)	0.037 (2)	−0.006 (3)	0.008 (2)	−0.0102 (17)
C8	0.046 (3)	0.044 (2)	0.0242 (17)	−0.005 (2)	−0.0048 (17)	−0.0050 (14)
C9	0.074 (4)	0.049 (3)	0.081 (3)	0.015 (3)	0.012 (3)	−0.004 (2)
C10	0.039 (3)	0.039 (2)	0.0298 (17)	0.004 (2)	0.0001 (16)	−0.0011 (15)
C11	0.045 (3)	0.052 (2)	0.0367 (19)	0.004 (3)	0.0018 (18)	0.0042 (18)
C12	0.047 (3)	0.057 (3)	0.040 (2)	−0.002 (3)	0.0105 (19)	0.0012 (19)
C13	0.051 (3)	0.046 (2)	0.0302 (17)	−0.001 (2)	−0.0081 (19)	0.0012 (16)
C14	0.051 (3)	0.042 (2)	0.0409 (19)	0.002 (3)	−0.003 (2)	0.0048 (17)
C15	0.043 (3)	0.045 (2)	0.038 (2)	0.003 (2)	0.0085 (19)	−0.0007 (17)
C16	0.075 (4)	0.068 (3)	0.053 (2)	−0.008 (3)	0.001 (3)	0.017 (2)
C17	0.040 (3)	0.043 (2)	0.0232 (16)	0.001 (2)	0.0030 (16)	−0.0016 (14)
C18	0.036 (3)	0.048 (2)	0.0275 (18)	0.000 (2)	0.0035 (16)	−0.0025 (18)
O19	0.045 (2)	0.0615 (19)	0.0292 (13)	0.001 (2)	0.0068 (11)	−0.0063 (12)
C20	0.050 (3)	0.070 (3)	0.0267 (18)	−0.006 (3)	0.0027 (19)	−0.0018 (17)
C21	0.042 (3)	0.046 (2)	0.0296 (17)	0.003 (2)	0.0038 (17)	0.0032 (15)
O22	0.0353 (17)	0.0492 (17)	0.0431 (14)	−0.0052 (15)	0.0026 (13)	−0.0066 (12)
O23	0.0347 (19)	0.0587 (19)	0.0510 (15)	0.0003 (17)	0.0023 (14)	−0.0021 (13)

Geometric parameters (Å, º)

O1—C2	1.443 (4)	C12—C13	1.388 (6)
O1—C17	1.405 (4)	C12—H121	0.960
C2—C3	1.516 (5)	C13—C14	1.384 (6)
C2—C10	1.512 (5)	C13—C16	1.513 (6)
C2—H21	1.000	C14—C15	1.398 (5)
C3—C4	1.399 (6)	C14—H141	0.965
C3—C8	1.389 (5)	C15—H151	0.934
C4—C5	1.379 (5)	C16—H161	0.946
C4—H41	0.958	C16—H162	0.974
C5—C6	1.377 (6)	C16—H163	0.965
C5—H51	0.995	C17—C18	1.507 (5)
C6—C7	1.387 (6)	C17—C21	1.524 (5)
C6—C9	1.504 (6)	C17—H171	0.997
C7—C8	1.373 (6)	C18—O19	1.338 (4)
C7—H71	0.957	C18—O23	1.200 (5)
C8—H81	0.940	O19—C20	1.465 (5)
C9—H91	0.961	C20—C21	1.527 (6)
C9—H92	0.953	C20—H201	0.985
C9—H93	0.958	C20—H202	0.971
C10—C11	1.401 (5)	C21—O22	1.409 (5)
C10—C15	1.372 (6)	C21—H211	0.982
C11—C12	1.388 (5)	O22—H26	0.847
C11—H111	0.961
C2—O1—C17	113.3 (3)	C13—C12—H121	119.1
O1—C2—C3	111.0 (3)	C12—C13—C14	118.6 (3)
O1—C2—C10	107.1 (3)	C12—C13—C16	120.6 (4)
C3—C2—C10	114.9 (3)	C14—C13—C16	120.8 (4)
O1—C2—H21	113.3	C13—C14—C15	120.2 (4)
C3—C2—H21	105.8	C13—C14—H141	119.8
C10—C2—H21	104.7	C15—C14—H141	120.1
C2—C3—C4	121.2 (3)	C14—C15—C10	121.4 (4)
C2—C3—C8	121.4 (4)	C14—C15—H151	119.3
C4—C3—C8	117.3 (4)	C10—C15—H151	119.3
C3—C4—C5	120.3 (4)	C13—C16—H161	108.6
C3—C4—H41	117.7	C13—C16—H162	108.5
C5—C4—H41	122.0	H161—C16—H162	110.6
C4—C5—C6	122.2 (4)	C13—C16—H163	108.9
C4—C5—H51	119.7	H161—C16—H163	108.4
C6—C5—H51	118.1	H162—C16—H163	111.8
C5—C6—C7	117.3 (4)	O1—C17—C18	112.3 (3)
C5—C6—C9	121.7 (4)	O1—C17—C21	114.1 (3)
C7—C6—C9	121.1 (4)	C18—C17—C21	102.7 (3)
C6—C7—C8	121.4 (4)	O1—C17—H171	110.2
C6—C7—H71	119.6	C18—C17—H171	106.9
C8—C7—H71	119.0	C21—C17—H171	110.2
C3—C8—C7	121.4 (4)	C17—C18—O19	109.5 (3)
C3—C8—H81	119.0	C17—C18—O23	128.6 (3)
C7—C8—H81	119.7	O19—C18—O23	122.0 (4)
C6—C9—H91	109.8	C18—O19—C20	109.5 (3)
C6—C9—H92	107.4	O19—C20—C21	105.3 (3)
H91—C9—H92	108.6	O19—C20—H201	107.8
C6—C9—H93	109.6	C21—C20—H201	112.1
H91—C9—H93	113.2	O19—C20—H202	111.4
H92—C9—H93	108.1	C21—C20—H202	112.5
C2—C10—C11	123.3 (4)	H201—C20—H202	107.7
C2—C10—C15	118.3 (3)	C20—C21—C17	99.7 (4)
C11—C10—C15	118.4 (3)	C20—C21—O22	108.7 (3)
C10—C11—C12	120.1 (4)	C17—C21—O22	111.7 (3)
C10—C11—H111	120.0	C20—C21—H211	111.9
C12—C11—H111	119.8	C17—C21—H211	111.6
C11—C12—C13	121.2 (4)	O22—C21—H211	112.5
C11—C12—H121	119.7	C21—O22—H26	128.3

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C4—H41···O23^i	0.96	2.53	3.461 (6)	165
O22—H26···O23^i	0.85	2.19	2.863 (6)	137

Symmetry code: (i) x+1, y, z.