tert-Butyl 2,2-dimethyl-4-(3-phenyl-2,5-dihydro­furan-2-yl)oxazolidine-3-carboxyl­ate

The title compound, C₂₀H₂₇NO₄, is a synthetic inter­mediate towards the preparation of novel furan­omycin derivatives. Its structure is consistent with the assumed anti selectivity of the allenylation step.

Key indicators

• Single-crystal X-ray study
• T = 173 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.029
• wR factor = 0.057
• Data-to-parameter ratio = 9.6

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          1
              C20 H27 N O4

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           27.48
           From the CIF: _reflns_number_total               2232
           Count of symmetry unique reflns         2235
           Completeness (_total/calc)             99.87%
           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 C10    = .          R
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C11    = .          S

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   1 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
   0 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

---

Computing details

Data collection: COLLECT (Nonius, 1998); cell refinement: DENZO and SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO and SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL-Plus (Sheldrick, 1991); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2003).

tert-Butyl 2,2-dimethyl-4-(3-phenyl-2,5-dihydrofuran-2-yl)oxazolidine-3-carboxylate

Crystal data

C20H27NO4	F(000) = 372
Mr = 345.43	Dx = 1.248 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 11172 reflections
a = 9.7530 (6) Å	θ = 3.0–27.5°
b = 9.3216 (8) Å	µ = 0.09 mm^−1
c = 10.792 (7) Å	T = 173 K
β = 110.462 (4)°	Block, colourless
V = 919.2 (6) Å^3	0.50 × 0.50 × 0.45 mm
Z = 2

Data collection

Nonius KappaCCD diffractometer	1472 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.028
Graphite monochromator	θmax = 27.5°, θmin = 3.0°
Detector resolution: 19 vertical, 18 horizontal pixels mm^-1	h = −12→12
380 frames via ω–rotation (ΔΩ= 1°) and two times 10 s per frame (four sets at different κ–angles) scans	k = −12→12
11172 measured reflections	l = −14→13
2232 independent reflections

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)] = 0.029	H-atom parameters constrained
wR(F^2) = 0.057	w = 1/[σ^2(Fo^2) + (0.0224P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.90	(Δ/σ)max < 0.001
2232 reflections	Δρmax = 0.16 e Å^−3
232 parameters	Δρmin = −0.12 e Å^−3
1 restraint	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.038 (2)

Special details

Experimental. IR (KBr pellet), cm^-1: 3012 (w), 2979 (m), 2952 (m), 2879 (m), 2837 (m), 1690 (s), 1393 (s), 1362 (s), 1083 (s), [α]_D²²: +127.5 (c 1/5, CHCl₃). NMR (most of the signals are duplicated due to the slow conformational inversion), ¹H (400 MHz, CDCl₃, room temperature): δ 7.53–7.28 (m, 5H), 6.27 (d, 1H), 5.81 (d, 1H), 4.84 (br s, 2H), 4.18 (dd, 1H), 3.83 (m, 1H), 3.71 (m, 1H), 1.69–1.45 (m, 15H); ¹³C (100.6 MHz, CDCl₃, room temperature): δ 152.0 (d), 139.8 (d), 132.5 (s), 128.7 (d), 128.1 (d), 126.4 (d), 123.4 (d), 94.6 (d), 84.4 (d), 80.1 (d), 76.1 (d), 62.7 (d), 59.1 (d), 28.6 (d), 25.8 (d), 24.3 (d), HRMS calculated for C₂₀H₂₇NO₄: [M + H]⁺ = 346.2018; found 346.2043 [M + H]⁺.

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
O1	0.19109 (15)	0.37201 (15)	−0.05010 (13)	0.0402 (4)
O2	−0.10422 (13)	0.38839 (15)	−0.27736 (12)	0.0338 (3)
O3	0.17075 (14)	0.26211 (16)	−0.48039 (14)	0.0376 (4)
O4	0.30194 (13)	0.45437 (14)	−0.36983 (12)	0.0300 (3)
N1	0.09469 (15)	0.39617 (17)	−0.34033 (14)	0.0276 (4)
C1	0.2773 (2)	0.7649 (2)	−0.04852 (18)	0.0290 (5)
C2	0.3607 (2)	0.7913 (2)	−0.1273 (2)	0.0359 (5)
H2	0.3949	0.7131	−0.1650	0.043*
C3	0.3945 (2)	0.9310 (2)	−0.1517 (2)	0.0421 (6)
H3	0.4528	0.9476	−0.2047	0.051*
C4	0.3439 (2)	1.0453 (3)	−0.0994 (2)	0.0435 (6)
H4	0.3660	1.1407	−0.1170	0.052*
C5	0.2610 (2)	1.0203 (2)	−0.0214 (2)	0.0439 (6)
H5	0.2259	1.0990	0.0150	0.053*
C6	0.2284 (2)	0.8821 (2)	0.00421 (18)	0.0358 (5)
H6	0.1716	0.8666	0.0588	0.043*
C7	0.2416 (2)	0.6176 (2)	−0.0206 (2)	0.0287 (5)
C8	0.2146 (2)	0.5703 (2)	0.0843 (2)	0.0363 (5)
H8	0.2131	0.6291	0.1557	0.044*
C9	0.1868 (2)	0.4128 (3)	0.0756 (2)	0.0423 (6)
H9A	0.2631	0.3617	0.1475	0.051*
H9B	0.0900	0.3911	0.0816	0.051*
C10	0.2281 (2)	0.4934 (2)	−0.11403 (18)	0.0300 (5)
H10	0.3248	0.4761	−0.1242	0.036*
C11	0.11126 (19)	0.5180 (2)	−0.25062 (17)	0.0265 (5)
H11	0.1358	0.6062	−0.2914	0.032*
C12	−0.0442 (2)	0.5302 (2)	−0.2491 (2)	0.0320 (5)
H12A	−0.0430	0.5628	−0.1614	0.038*
H12B	−0.1023	0.5990	−0.3171	0.038*
C13	−0.0493 (2)	0.3239 (2)	−0.37114 (19)	0.0313 (5)
C14	−0.0338 (2)	0.1652 (2)	−0.3410 (2)	0.0406 (6)
H14A	0.0327	0.1506	−0.2499	0.061*
H14B	0.0059	0.1175	−0.4021	0.061*
H14C	−0.1299	0.1246	−0.3516	0.061*
C15	−0.1492 (2)	0.3588 (2)	−0.51085 (19)	0.0402 (6)
H15A	−0.2427	0.3087	−0.5298	0.060*
H15B	−0.1031	0.3276	−0.5737	0.060*
H15C	−0.1665	0.4625	−0.5193	0.060*
C16	0.1879 (2)	0.3624 (2)	−0.40352 (18)	0.0294 (5)
C17	0.43261 (19)	0.4217 (2)	−0.40335 (19)	0.0292 (5)
C18	0.5320 (2)	0.5473 (2)	−0.3428 (2)	0.0376 (5)
H18A	0.4842	0.6368	−0.3829	0.056*
H18B	0.6243	0.5366	−0.3590	0.056*
H18C	0.5519	0.5497	−0.2473	0.056*
C19	0.3953 (2)	0.4190 (2)	−0.55272 (18)	0.0346 (5)
H19A	0.3294	0.3385	−0.5906	0.052*
H19B	0.4854	0.4077	−0.5727	0.052*
H19C	0.3472	0.5091	−0.5910	0.052*
C20	0.4995 (2)	0.2824 (2)	−0.3386 (2)	0.0383 (6)
H20A	0.5142	0.2861	−0.2441	0.057*
H20B	0.5939	0.2679	−0.3500	0.057*
H20C	0.4338	0.2027	−0.3799	0.057*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0570 (9)	0.0312 (9)	0.0288 (8)	−0.0044 (7)	0.0104 (7)	0.0004 (7)
O2	0.0313 (7)	0.0401 (9)	0.0354 (7)	−0.0051 (7)	0.0184 (6)	−0.0060 (8)
O3	0.0403 (8)	0.0389 (9)	0.0377 (8)	−0.0093 (8)	0.0190 (7)	−0.0152 (8)
O4	0.0252 (7)	0.0330 (8)	0.0356 (8)	−0.0048 (6)	0.0155 (6)	−0.0065 (6)
N1	0.0244 (8)	0.0310 (10)	0.0290 (8)	−0.0072 (8)	0.0114 (7)	−0.0093 (9)
C1	0.0298 (11)	0.0310 (12)	0.0228 (11)	−0.0016 (10)	0.0051 (9)	−0.0029 (10)
C2	0.0355 (12)	0.0353 (14)	0.0376 (13)	−0.0027 (10)	0.0139 (11)	−0.0051 (11)
C3	0.0409 (12)	0.0464 (17)	0.0398 (14)	−0.0077 (11)	0.0150 (11)	0.0034 (12)
C4	0.0519 (15)	0.0322 (14)	0.0376 (13)	−0.0094 (12)	0.0044 (12)	0.0004 (11)
C5	0.0551 (15)	0.0363 (15)	0.0372 (13)	0.0053 (12)	0.0122 (12)	−0.0024 (11)
C6	0.0441 (12)	0.0332 (14)	0.0305 (11)	0.0018 (11)	0.0137 (9)	−0.0026 (11)
C7	0.0285 (11)	0.0308 (12)	0.0255 (11)	−0.0012 (9)	0.0078 (9)	−0.0027 (10)
C8	0.0411 (12)	0.0389 (14)	0.0277 (12)	−0.0048 (10)	0.0106 (10)	−0.0072 (11)
C9	0.0493 (13)	0.0463 (15)	0.0302 (11)	−0.0080 (12)	0.0124 (10)	0.0020 (11)
C10	0.0310 (11)	0.0293 (12)	0.0287 (11)	0.0011 (9)	0.0090 (9)	0.0003 (10)
C11	0.0273 (10)	0.0274 (12)	0.0257 (11)	−0.0010 (9)	0.0105 (9)	−0.0022 (9)
C12	0.0311 (11)	0.0344 (14)	0.0318 (11)	0.0005 (10)	0.0126 (9)	−0.0019 (10)
C13	0.0266 (11)	0.0386 (13)	0.0307 (12)	−0.0080 (9)	0.0125 (9)	−0.0063 (10)
C14	0.0395 (13)	0.0362 (15)	0.0497 (14)	−0.0097 (10)	0.0201 (12)	−0.0033 (12)
C15	0.0327 (11)	0.0523 (16)	0.0331 (11)	−0.0090 (11)	0.0084 (9)	−0.0061 (12)
C16	0.0291 (11)	0.0335 (14)	0.0258 (11)	−0.0053 (10)	0.0099 (9)	−0.0005 (11)
C17	0.0249 (10)	0.0340 (13)	0.0320 (11)	0.0016 (9)	0.0140 (9)	0.0028 (10)
C18	0.0280 (11)	0.0390 (14)	0.0483 (13)	−0.0029 (10)	0.0164 (10)	0.0019 (11)
C19	0.0346 (11)	0.0386 (14)	0.0349 (12)	0.0051 (10)	0.0175 (9)	0.0051 (11)
C20	0.0351 (12)	0.0407 (15)	0.0389 (13)	0.0068 (11)	0.0126 (10)	0.0046 (11)

Geometric parameters (Å, º)

O1—C9	1.423 (2)	C9—H9B	0.9900
O1—C10	1.435 (2)	C10—C11	1.533 (3)
O2—C13	1.432 (2)	C10—H10	1.0000
O2—C12	1.435 (2)	C11—C12	1.526 (3)
O3—C16	1.222 (2)	C11—H11	1.0000
O4—C16	1.350 (2)	C12—H12A	0.9900
O4—C17	1.473 (2)	C12—H12B	0.9900
N1—C16	1.350 (2)	C13—C14	1.511 (3)
N1—C11	1.464 (2)	C13—C15	1.517 (3)
N1—C13	1.487 (2)	C14—H14A	0.9800
C1—C2	1.389 (3)	C14—H14B	0.9800
C1—C6	1.390 (3)	C14—H14C	0.9800
C1—C7	1.474 (3)	C15—H15A	0.9800
C2—C3	1.391 (3)	C15—H15B	0.9800
C2—H2	0.9500	C15—H15C	0.9800
C3—C4	1.375 (3)	C17—C20	1.510 (3)
C3—H3	0.9500	C17—C18	1.515 (3)
C4—C5	1.376 (3)	C17—C19	1.524 (3)
C4—H4	0.9500	C18—H18A	0.9800
C5—C6	1.378 (3)	C18—H18B	0.9800
C5—H5	0.9500	C18—H18C	0.9800
C6—H6	0.9500	C19—H19A	0.9800
C7—C8	1.324 (3)	C19—H19B	0.9800
C7—C10	1.511 (3)	C19—H19C	0.9800
C8—C9	1.490 (3)	C20—H20A	0.9800
C8—H8	0.9500	C20—H20B	0.9800
C9—H9A	0.9900	C20—H20C	0.9800
C9—O1—C10	110.08 (16)	C11—C12—H12A	110.7
C13—O2—C12	108.16 (13)	O2—C12—H12B	110.7
C16—O4—C17	120.33 (15)	C11—C12—H12B	110.7
C16—N1—C11	125.20 (16)	H12A—C12—H12B	108.8
C16—N1—C13	122.10 (15)	O2—C13—N1	102.07 (14)
C11—N1—C13	112.13 (13)	O2—C13—C14	107.05 (16)
C2—C1—C6	118.0 (2)	N1—C13—C14	112.32 (16)
C2—C1—C7	121.37 (19)	O2—C13—C15	110.07 (16)
C6—C1—C7	120.61 (17)	N1—C13—C15	110.72 (15)
C1—C2—C3	120.6 (2)	C14—C13—C15	113.88 (18)
C1—C2—H2	119.7	C13—C14—H14A	109.5
C3—C2—H2	119.7	C13—C14—H14B	109.5
C4—C3—C2	120.34 (19)	H14A—C14—H14B	109.5
C4—C3—H3	119.8	C13—C14—H14C	109.5
C2—C3—H3	119.8	H14A—C14—H14C	109.5
C3—C4—C5	119.5 (2)	H14B—C14—H14C	109.5
C3—C4—H4	120.3	C13—C15—H15A	109.5
C5—C4—H4	120.3	C13—C15—H15B	109.5
C4—C5—C6	120.4 (2)	H15A—C15—H15B	109.5
C4—C5—H5	119.8	C13—C15—H15C	109.5
C6—C5—H5	119.8	H15A—C15—H15C	109.5
C5—C6—C1	121.09 (19)	H15B—C15—H15C	109.5
C5—C6—H6	119.5	O3—C16—O4	124.96 (16)
C1—C6—H6	119.5	O3—C16—N1	124.37 (17)
C8—C7—C1	128.09 (18)	O4—C16—N1	110.67 (17)
C8—C7—C10	108.58 (18)	O4—C17—C20	109.58 (15)
C1—C7—C10	123.33 (17)	O4—C17—C18	102.26 (15)
C7—C8—C9	111.12 (19)	C20—C17—C18	110.93 (16)
C7—C8—H8	124.4	O4—C17—C19	110.87 (14)
C9—C8—H8	124.4	C20—C17—C19	112.31 (17)
O1—C9—C8	104.96 (18)	C18—C17—C19	110.44 (16)
O1—C9—H9A	110.8	C17—C18—H18A	109.5
C8—C9—H9A	110.8	C17—C18—H18B	109.5
O1—C9—H9B	110.8	H18A—C18—H18B	109.5
C8—C9—H9B	110.8	C17—C18—H18C	109.5
H9A—C9—H9B	108.8	H18A—C18—H18C	109.5
O1—C10—C7	105.15 (15)	H18B—C18—H18C	109.5
O1—C10—C11	110.67 (15)	C17—C19—H19A	109.5
C7—C10—C11	112.94 (16)	C17—C19—H19B	109.5
O1—C10—H10	109.3	H19A—C19—H19B	109.5
C7—C10—H10	109.3	C17—C19—H19C	109.5
C11—C10—H10	109.3	H19A—C19—H19C	109.5
N1—C11—C12	100.65 (14)	H19B—C19—H19C	109.5
N1—C11—C10	113.15 (16)	C17—C20—H20A	109.5
C12—C11—C10	114.06 (15)	C17—C20—H20B	109.5
N1—C11—H11	109.5	H20A—C20—H20B	109.5
C12—C11—H11	109.5	C17—C20—H20C	109.5
C10—C11—H11	109.5	H20A—C20—H20C	109.5
O2—C12—C11	105.17 (15)	H20B—C20—H20C	109.5
O2—C12—H12A	110.7
C6—C1—C2—C3	0.3 (3)	O1—C10—C11—N1	−60.73 (19)
C7—C1—C2—C3	−179.37 (19)	C7—C10—C11—N1	−178.30 (14)
C1—C2—C3—C4	−0.9 (3)	O1—C10—C11—C12	53.5 (2)
C2—C3—C4—C5	0.8 (3)	C7—C10—C11—C12	−64.0 (2)
C3—C4—C5—C6	−0.1 (3)	C13—O2—C12—C11	−36.31 (19)
C4—C5—C6—C1	−0.5 (3)	N1—C11—C12—O2	26.85 (18)
C2—C1—C6—C5	0.4 (3)	C10—C11—C12—O2	−94.63 (18)
C7—C1—C6—C5	−179.9 (2)	C12—O2—C13—N1	28.89 (18)
C2—C1—C7—C8	152.4 (2)	C12—O2—C13—C14	147.05 (16)
C6—C1—C7—C8	−27.4 (3)	C12—O2—C13—C15	−88.70 (18)
C2—C1—C7—C10	−28.6 (3)	C16—N1—C13—O2	177.31 (16)
C6—C1—C7—C10	151.67 (19)	C11—N1—C13—O2	−10.93 (19)
C1—C7—C8—C9	−178.60 (19)	C16—N1—C13—C14	63.0 (2)
C10—C7—C8—C9	2.3 (2)	C11—N1—C13—C14	−125.26 (18)
C10—O1—C9—C8	3.3 (2)	C16—N1—C13—C15	−65.6 (2)
C7—C8—C9—O1	−3.5 (2)	C11—N1—C13—C15	106.20 (17)
C9—O1—C10—C7	−2.09 (19)	C17—O4—C16—O3	−12.9 (3)
C9—O1—C10—C11	−124.34 (16)	C17—O4—C16—N1	166.95 (15)
C8—C7—C10—O1	−0.2 (2)	C11—N1—C16—O3	−178.32 (18)
C1—C7—C10—O1	−179.34 (17)	C13—N1—C16—O3	−7.7 (3)
C8—C7—C10—C11	120.61 (18)	C11—N1—C16—O4	1.8 (2)
C1—C7—C10—C11	−58.6 (2)	C13—N1—C16—O4	172.44 (16)
C16—N1—C11—C12	161.82 (17)	C16—O4—C17—C20	−59.8 (2)
C13—N1—C11—C12	−9.64 (19)	C16—O4—C17—C18	−177.57 (15)
C16—N1—C11—C10	−76.1 (2)	C16—O4—C17—C19	64.7 (2)
C13—N1—C11—C10	112.48 (17)