N-(Fluoren-9-ylmethoxy-carbon-yl)-l-leucine.

THE TITLE COMPOUND [SYSTEMATIC NAME: fluoren-9-yl N-(1-carb-oxy-3-methyl-butyl)carbamate], C(21)H(23)NO(4), exhibits torsion angles that vary from the typical values found in other Fmoc-protected amino acids, viz. the orientations of the fluorene and carboxyl groups [C-O-C-C = 93.8 (2) and N-C-C=O = -23.6 (2)°]. The crystal structure exhibits two inter-molecular hydrogen bonds (O-H⋯O and N-H⋯O) that link the mol-ecules into two-dimensional sheets parallel to the ab plane.

Related literature

For related literature on the structures of N-α-Fmoc-protected amino acids, see: Valle et al. (1984 ▶); Yamada et al. (2008 ▶).

Experimental

Crystal data

C21H23NO4

M = 353.40

Orthorhombic,

a = 5.4953 (1) Å

b = 14.2700 (3) Å

c = 24.3759 (6) Å

V = 1911.51 (7) Å3

Z = 4

Mo Kα radiation

μ = 0.09 mm−1

T = 150 K

0.40 × 0.08 × 0.06 mm

Data collection

Rigaku AFC-8 diffractometer with Saturn70 CCD detector

Absorption correction: none

40257 measured reflections

3207 independent reflections

2906 reflections with I > 2σ(I)

R int = 0.055

Refinement

R[F 2 > 2σ(F 2)] = 0.039

wR(F 2) = 0.111

S = 1.09

3207 reflections

327 parameters

All H-atom parameters refined

Δρmax = 0.27 e Å−3

Δρmin = −0.26 e Å−3

Data collection: CrystalClear (Rigaku/MSC, 2005 ▶); cell refinement: HKL-2000 (Otwinowski & Minor, 1997 ▶); data reduction: HKL-2000; program(s) used to solve structure: SIR2004 (Burla et al., 2005 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXL97.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808014372/fl2198sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808014372/fl2198Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C21H23NO4	F000 = 752
Mr = 353.40	Dx = 1.228 Mg m−3
Orthorhombic, P212121	Mo Kα radiation λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 40402 reflections
a = 5.49530 (10) Å	θ = 2.2–30.0º
b = 14.2700 (3) Å	µ = 0.09 mm−1
c = 24.3759 (6) Å	T = 150 K
V = 1911.51 (7) Å3	Needle, colourless
Z = 4	0.40 × 0.08 × 0.06 mm

Rigaku AFC-8 diffractometer with Saturn70 CCD detector	3207 independent reflections
Radiation source: fine-focus rotating anode	2906 reflections with I > 2σ(I)
Monochromator: confocal	Rint = 0.055
Detector resolution: 28.5714 pixels mm-1	θmax = 30.0º
T = 150 K	θmin = 2.2º
ω scans	h = −7→7
Absorption correction: none	k = −20→20
40257 measured reflections	l = −34→34

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.039	All H-atom parameters refined
wR(F2) = 0.111	w = 1/[σ2(Fo2) + (0.0687P)2 + 0.1717P] where P = (Fo2 + 2Fc2)/3
S = 1.09	(Δ/σ)max < 0.001
3207 reflections	Δρmax = 0.27 e Å−3
327 parameters	Δρmin = −0.25 e Å−3
Primary atom site location: structure-invariant direct methods	Extinction correction: none

Experimental. All Friedel pairs were merged, and all f''s of containing atoms were set to zero.

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.

	x	y	z	Uiso*/Ueq
O1	−0.3755 (2)	0.42665 (9)	0.27853 (7)	0.0421 (3)
O2	0.0123 (2)	0.47101 (9)	0.26982 (7)	0.0455 (4)
H2H	−0.047 (5)	0.526 (2)	0.2667 (11)	0.055 (7)*
O3	0.1016 (2)	0.15166 (8)	0.23545 (6)	0.0360 (3)
O4	0.4680 (2)	0.22208 (8)	0.22403 (5)	0.0306 (2)
N1	0.1792 (2)	0.29706 (9)	0.26957 (6)	0.0284 (3)
H1N	0.280 (5)	0.3438 (18)	0.2738 (9)	0.044 (6)*
C1	−0.0651 (3)	0.31083 (10)	0.29096 (7)	0.0287 (3)
H1	−0.171 (4)	0.2659 (15)	0.2718 (9)	0.035 (5)*
C2	−0.0783 (4)	0.29621 (13)	0.35339 (8)	0.0406 (4)
H2A	0.047 (5)	0.3372 (19)	0.3712 (10)	0.048 (7)*
H2B	−0.225 (6)	0.322 (2)	0.3692 (13)	0.065 (8)*
C3	−0.0497 (4)	0.19389 (13)	0.37135 (8)	0.0413 (4)
H3	0.102 (5)	0.1685 (18)	0.3516 (10)	0.048 (7)*
C4	−0.2695 (5)	0.13470 (17)	0.35502 (14)	0.0601 (7)
H4A	−0.312 (6)	0.1369 (19)	0.3131 (11)	0.060 (8)*
H4B	−0.387 (8)	0.163 (3)	0.3755 (15)	0.088 (11)*
H4C	−0.262 (6)	0.065 (2)	0.3677 (13)	0.072 (9)*
C5	0.0014 (9)	0.18903 (19)	0.43291 (10)	0.0705 (9)
H5A	0.163 (8)	0.227 (3)	0.4437 (15)	0.093 (12)*
H5B	0.017 (6)	0.124 (2)	0.4463 (11)	0.060 (8)*
H5C	−0.127 (7)	0.223 (2)	0.4509 (13)	0.072 (9)*
C6	−0.1606 (3)	0.40869 (10)	0.27831 (7)	0.0299 (3)
C7	0.2373 (3)	0.21843 (10)	0.24241 (6)	0.0261 (3)
C8	0.5484 (3)	0.14752 (11)	0.18786 (6)	0.0289 (3)
H8A	0.476 (5)	0.0932 (16)	0.1976 (9)	0.034 (5)*
H8B	0.721 (5)	0.1412 (15)	0.1960 (9)	0.034 (5)*
C9	0.5153 (3)	0.17588 (11)	0.12778 (7)	0.0291 (3)
H9	0.337 (5)	0.1858 (16)	0.1193 (9)	0.043 (6)*
C10	0.6613 (3)	0.26233 (11)	0.11325 (7)	0.0308 (3)
C11	0.6335 (4)	0.35445 (12)	0.13131 (8)	0.0385 (4)
H11	0.504 (5)	0.3707 (16)	0.1573 (9)	0.035 (5)*
C12	0.8001 (4)	0.42145 (13)	0.11327 (9)	0.0456 (4)
H12	0.783 (5)	0.4852 (19)	0.1253 (10)	0.054 (7)*
C13	0.9889 (4)	0.39782 (15)	0.07795 (8)	0.0459 (5)
H13	1.117 (5)	0.4495 (19)	0.0642 (11)	0.057 (7)*
C14	1.0166 (4)	0.30626 (15)	0.05954 (8)	0.0408 (4)
H14	1.148 (5)	0.2884 (16)	0.0338 (10)	0.048 (6)*
C15	0.8514 (3)	0.23871 (12)	0.07728 (7)	0.0323 (3)
C16	0.8333 (3)	0.13832 (12)	0.06424 (6)	0.0329 (3)
C17	0.9738 (4)	0.08170 (16)	0.03029 (8)	0.0437 (4)
H17	1.114 (5)	0.1107 (17)	0.0111 (10)	0.048 (7)*
C18	0.9091 (5)	−0.01199 (16)	0.02442 (8)	0.0505 (5)
H18	1.003 (6)	−0.0545 (19)	0.0001 (11)	0.060 (7)*
C19	0.7076 (5)	−0.04829 (14)	0.05165 (8)	0.0473 (5)
H19	0.671 (5)	−0.1136 (19)	0.0461 (10)	0.053 (7)*
C20	0.5670 (4)	0.00808 (12)	0.08599 (8)	0.0392 (4)
H20	0.423 (5)	−0.0159 (18)	0.1060 (11)	0.053 (7)*
C21	0.6305 (3)	0.10141 (11)	0.09189 (6)	0.0317 (3)

	U11	U22	U33	U12	U13	U23
O1	0.0236 (6)	0.0258 (5)	0.0769 (9)	0.0009 (4)	0.0034 (6)	−0.0057 (6)
O2	0.0258 (6)	0.0197 (5)	0.0910 (11)	−0.0004 (4)	−0.0005 (7)	0.0087 (6)
O3	0.0236 (5)	0.0220 (5)	0.0623 (7)	−0.0025 (4)	0.0012 (5)	−0.0085 (5)
O4	0.0245 (5)	0.0259 (5)	0.0415 (6)	−0.0027 (4)	0.0051 (5)	−0.0058 (4)
N1	0.0232 (6)	0.0190 (5)	0.0430 (7)	−0.0026 (5)	0.0012 (5)	−0.0035 (5)
C1	0.0246 (7)	0.0194 (6)	0.0423 (8)	−0.0004 (5)	0.0036 (6)	−0.0008 (5)
C2	0.0521 (11)	0.0276 (7)	0.0422 (8)	0.0008 (8)	0.0104 (8)	0.0005 (6)
C3	0.0447 (10)	0.0325 (8)	0.0466 (9)	0.0005 (8)	0.0056 (8)	0.0076 (7)
C4	0.0468 (13)	0.0424 (11)	0.0911 (19)	−0.0093 (10)	0.0005 (13)	0.0225 (12)
C5	0.115 (3)	0.0485 (12)	0.0480 (11)	0.0009 (17)	0.0066 (16)	0.0115 (10)
C6	0.0243 (7)	0.0214 (6)	0.0440 (8)	−0.0003 (5)	0.0012 (6)	−0.0026 (5)
C7	0.0229 (6)	0.0204 (6)	0.0351 (7)	0.0002 (5)	−0.0014 (5)	0.0006 (5)
C8	0.0270 (7)	0.0235 (6)	0.0361 (7)	0.0019 (6)	0.0027 (6)	−0.0013 (5)
C9	0.0249 (7)	0.0254 (7)	0.0370 (7)	−0.0001 (6)	−0.0018 (6)	−0.0007 (5)
C10	0.0282 (8)	0.0287 (7)	0.0353 (7)	−0.0019 (6)	−0.0020 (6)	0.0030 (6)
C11	0.0407 (10)	0.0293 (8)	0.0455 (9)	−0.0012 (7)	0.0029 (8)	0.0011 (6)
C12	0.0529 (12)	0.0301 (8)	0.0537 (10)	−0.0085 (9)	0.0003 (10)	0.0034 (7)
C13	0.0463 (11)	0.0412 (10)	0.0500 (10)	−0.0140 (9)	−0.0004 (9)	0.0089 (8)
C14	0.0346 (9)	0.0490 (10)	0.0389 (8)	−0.0064 (8)	0.0021 (7)	0.0082 (7)
C15	0.0305 (8)	0.0338 (7)	0.0326 (7)	−0.0004 (6)	−0.0026 (6)	0.0037 (6)
C16	0.0325 (8)	0.0364 (8)	0.0296 (6)	0.0047 (7)	−0.0040 (6)	0.0006 (6)
C17	0.0427 (10)	0.0523 (11)	0.0360 (8)	0.0134 (9)	−0.0003 (8)	−0.0033 (7)
C18	0.0625 (14)	0.0489 (11)	0.0401 (9)	0.0206 (11)	−0.0069 (9)	−0.0108 (8)
C19	0.0671 (14)	0.0341 (9)	0.0406 (8)	0.0092 (9)	−0.0122 (10)	−0.0079 (7)
C20	0.0483 (11)	0.0299 (8)	0.0395 (8)	−0.0001 (8)	−0.0082 (8)	−0.0026 (6)
C21	0.0330 (8)	0.0298 (7)	0.0324 (7)	0.0042 (6)	−0.0060 (6)	−0.0021 (6)

O1—C6	1.208 (2)	C8—H8B	0.97 (2)
O2—C6	1.318 (2)	C9—C10	1.514 (2)
O2—H2H	0.85 (3)	C9—C21	1.515 (2)
O3—C7	1.2217 (18)	C9—H9	1.01 (3)
O4—C7	1.3460 (19)	C10—C11	1.395 (2)
O4—C8	1.4506 (18)	C10—C15	1.405 (2)
N1—C7	1.3413 (18)	C11—C12	1.395 (3)
N1—C1	1.453 (2)	C11—H11	0.98 (2)
N1—H1N	0.87 (3)	C12—C13	1.390 (3)
C1—C6	1.523 (2)	C12—H12	0.96 (3)
C1—C2	1.538 (2)	C13—C14	1.390 (3)
C1—H1	0.98 (2)	C13—H13	1.07 (3)
C2—C3	1.532 (3)	C14—C15	1.393 (3)
C2—H2A	1.00 (3)	C14—H14	0.99 (3)
C2—H2B	0.96 (3)	C15—C16	1.471 (2)
C3—C4	1.527 (3)	C16—C17	1.391 (3)
C3—C5	1.528 (3)	C16—C21	1.405 (3)
C3—H3	1.03 (3)	C17—C18	1.391 (3)
C4—H4A	1.05 (3)	C17—H17	0.99 (3)
C4—H4B	0.91 (4)	C18—C19	1.391 (4)
C4—H4C	1.04 (3)	C18—H18	0.99 (3)
C5—H5A	1.08 (4)	C19—C20	1.395 (3)
C5—H5B	0.98 (3)	C19—H19	0.96 (3)
C5—H5C	0.96 (4)	C20—C21	1.384 (2)
C8—C9	1.530 (2)	C20—H20	0.99 (3)
C8—H8A	0.90 (2)
C6—O2—H2H	111.1 (19)	C9—C8—H8B	109.5 (13)
C7—O4—C8	117.44 (12)	H8A—C8—H8B	107 (2)
C7—N1—C1	120.66 (13)	C10—C9—C21	102.41 (13)
C7—N1—H1N	123.1 (16)	C10—C9—C8	112.11 (13)
C1—N1—H1N	116.1 (16)	C21—C9—C8	108.51 (13)
N1—C1—C6	111.69 (13)	C10—C9—H9	110.6 (13)
N1—C1—C2	112.36 (15)	C21—C9—H9	112.6 (13)
C6—C1—C2	107.96 (13)	C8—C9—H9	110.4 (13)
N1—C1—H1	106.7 (13)	C11—C10—C15	120.30 (16)
C6—C1—H1	107.3 (13)	C11—C10—C9	129.51 (16)
C2—C1—H1	110.7 (13)	C15—C10—C9	110.16 (14)
C3—C2—C1	114.03 (14)	C10—C11—C12	118.34 (19)
C3—C2—H2A	111.3 (15)	C10—C11—H11	120.5 (13)
C1—C2—H2A	108.5 (14)	C12—C11—H11	121.1 (13)
C3—C2—H2B	109.2 (18)	C13—C12—C11	121.27 (19)
C1—C2—H2B	112.6 (18)	C13—C12—H12	119.4 (17)
H2A—C2—H2B	100 (2)	C11—C12—H12	119.3 (17)
C4—C3—C5	112.1 (2)	C14—C13—C12	120.65 (18)
C4—C3—C2	111.80 (19)	C14—C13—H13	118.2 (15)
C5—C3—C2	110.04 (18)	C12—C13—H13	121.1 (14)
C4—C3—H3	108.9 (14)	C13—C14—C15	118.62 (19)
C5—C3—H3	107.1 (14)	C13—C14—H14	121.8 (14)
C2—C3—H3	106.6 (15)	C15—C14—H14	119.6 (14)
C3—C4—H4A	114.4 (17)	C14—C15—C10	120.82 (17)
C3—C4—H4B	100 (2)	C14—C15—C16	130.61 (18)
H4A—C4—H4B	111 (3)	C10—C15—C16	108.56 (15)
C3—C4—H4C	115 (2)	C17—C16—C21	120.53 (18)
H4A—C4—H4C	109 (2)	C17—C16—C15	131.08 (19)
H4B—C4—H4C	107 (3)	C21—C16—C15	108.36 (15)
C3—C5—H5A	112 (2)	C16—C17—C18	118.6 (2)
C3—C5—H5B	112.7 (16)	C16—C17—H17	118.0 (14)
H5A—C5—H5B	109 (3)	C18—C17—H17	123.4 (14)
C3—C5—H5C	107 (2)	C17—C18—C19	120.8 (2)
H5A—C5—H5C	104 (3)	C17—C18—H18	121.1 (16)
H5B—C5—H5C	112 (3)	C19—C18—H18	118.0 (16)
O1—C6—O2	124.21 (15)	C18—C19—C20	120.84 (19)
O1—C6—C1	122.02 (15)	C18—C19—H19	117.2 (17)
O2—C6—C1	113.70 (14)	C20—C19—H19	121.9 (17)
O3—C7—N1	125.15 (15)	C21—C20—C19	118.5 (2)
O3—C7—O4	123.98 (14)	C21—C20—H20	118.9 (15)
N1—C7—O4	110.87 (13)	C19—C20—H20	122.6 (15)
O4—C8—C9	110.58 (13)	C20—C21—C16	120.73 (16)
O4—C8—H8A	109.7 (14)	C20—C21—C9	129.00 (17)
C9—C8—H8A	115.2 (14)	C16—C21—C9	110.22 (14)
O4—C8—H8B	104.0 (13)
C7—N1—C1—C6	−134.51 (15)	C13—C14—C15—C10	−0.3 (3)
C7—N1—C1—C2	103.99 (16)	C13—C14—C15—C16	178.99 (18)
N1—C1—C2—C3	−70.9 (2)	C11—C10—C15—C14	0.7 (3)
C6—C1—C2—C3	165.48 (17)	C9—C10—C15—C14	−177.72 (16)
C1—C2—C3—C4	−69.5 (3)	C11—C10—C15—C16	−178.72 (16)
C1—C2—C3—C5	165.2 (2)	C9—C10—C15—C16	2.82 (18)
N1—C1—C6—O1	159.29 (17)	C14—C15—C16—C17	−0.5 (3)
C2—C1—C6—O1	−76.7 (2)	C10—C15—C16—C17	178.86 (18)
N1—C1—C6—O2	−23.6 (2)	C14—C15—C16—C21	−178.76 (18)
C2—C1—C6—O2	100.39 (19)	C10—C15—C16—C21	0.63 (18)
C1—N1—C7—O3	−3.6 (2)	C21—C16—C17—C18	−0.1 (3)
C1—N1—C7—O4	177.08 (13)	C15—C16—C17—C18	−178.11 (18)
C8—O4—C7—O3	8.3 (2)	C16—C17—C18—C19	0.3 (3)
C8—O4—C7—N1	−172.31 (13)	C17—C18—C19—C20	−0.7 (3)
C7—O4—C8—C9	93.78 (16)	C18—C19—C20—C21	0.8 (3)
O4—C8—C9—C10	60.54 (17)	C19—C20—C21—C16	−0.5 (3)
O4—C8—C9—C21	172.91 (13)	C19—C20—C21—C9	−177.57 (17)
C21—C9—C10—C11	176.89 (18)	C17—C16—C21—C20	0.2 (2)
C8—C9—C10—C11	−67.0 (2)	C15—C16—C21—C20	178.61 (16)
C21—C9—C10—C15	−4.84 (17)	C17—C16—C21—C9	177.72 (15)
C8—C9—C10—C15	111.28 (16)	C15—C16—C21—C9	−3.83 (18)
C15—C10—C11—C12	−0.7 (3)	C10—C9—C21—C20	−177.46 (17)
C9—C10—C11—C12	177.40 (17)	C8—C9—C21—C20	63.8 (2)
C10—C11—C12—C13	0.3 (3)	C10—C9—C21—C16	5.24 (17)
C11—C12—C13—C14	0.1 (3)	C8—C9—C21—C16	−113.45 (15)
C12—C13—C14—C15	−0.1 (3)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2H···O3i	0.85 (3)	1.82 (3)	2.6558 (17)	167 (3)
N1—H1N···O1ii	0.87 (3)	2.24 (3)	3.0751 (18)	161 (2)
C8—H8A···O1iii	0.90 (2)	2.51 (2)	3.392 (2)	166 (2)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2H⋯O3i	0.85 (3)	1.82 (3)	2.6558 (17)	167 (3)
N1—H1N⋯O1ii	0.87 (3)	2.24 (3)	3.0751 (18)	161 (2)
C8—H8A⋯O1iii	0.90 (2)	2.51 (2)	3.392 (2)	166 (2)

Symmetry codes: (i) ; (ii) ; (iii) .