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Treatment of 9-lithiated fluorene with pivaloyl chloride provided ap-9-pivaloylfluorene, (1), the major product, and a minor product ultimately identified as the title compound, C23H26O2, (2). The latter was also formed directly, but slowly, from 9-lithiated-(1) treated with pivaloyl chloride. Although (1) exists exclusively as its less sterically restricted ap rotamer, its sp2-hybridized anion sterically impedes reaction at the 9-position from either face. While 9-lithiated-(1) is exclusively, but slowly, 9-methylated with methyl iodide, reaction with pivaloyl chloride, also slow, leads only to the O-acylated product, (2). The protons of the tert-butyl-C=C moiety approach a proton on the fluorene ring to well within the sum of their van der Waals radii, resulting in significant molecular compression, strain and distortion. For example, distortion in the moiety C=C(O)(C) is exhibited by the enlargement of C=C-C angle to 130.6 (2)° at the expense of the corresponding `equivalent' C=C-O angle, which is compressed to 116.46 (19)°.
Supporting information
CCDC reference: 153913
Data collection: MSC/AFC Diffractometer Control Software
(Molecular Structure Corporation,1996); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: PROCESS in TEXSAN (Molecular Structure Corporation, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: LS in TEXSAN and SHELXL97 (Sheldrick, 1997); software used to prepare material for publication: TEXSAN, SHELXL97 and PLATON (Spek, 2000).
9-(2',2'-dimethyl-1'-pivaloxypropylidine)fluorene
top
Crystal data top
C23H26O2 | Dx = 1.151 Mg m−3 |
Mr = 334.44 | Melting point = 404–405 K |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71069 Å |
a = 11.1247 (15) Å | Cell parameters from 24 reflections |
b = 10.4604 (10) Å | θ = 18.8–20.9° |
c = 16.6259 (14) Å | µ = 0.07 mm−1 |
β = 93.951 (9)° | T = 296 K |
V = 1930.1 (4) Å3 | Prism, colorless |
Z = 4 | 0.54 × 0.49 × 0.43 mm |
F(000) = 720 | |
Data collection top
Rigaku AFC-5S diffractometer | Rint = 0.017 |
Radiation source: X-ray tube | θmax = 25.0°, θmin = 2.1° |
Graphite monochromator | h = 0→13 |
ω scans | k = 0→12 |
3589 measured reflections | l = −19→19 |
3401 independent reflections | 3 standard reflections every 100 reflections |
2019 reflections with I > 2σ(I) | intensity decay: 0.2% |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.050 | H-atom parameters constrained |
wR(F2) = 0.153 | w = 1/[σ2(Fo2) + (0.0734P)2 + 0.2129P] where P = (Fo2 + 2Fc2)/3 |
S = 1.03 | (Δ/σ)max < 0.001 |
3401 reflections | Δρmax = 0.17 e Å−3 |
233 parameters | Δρmin = −0.16 e Å−3 |
0 restraints | Extinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.017 (2) |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
O1 | −0.07492 (13) | −0.97025 (15) | −0.23828 (8) | 0.0542 (4) | |
O2 | 0.07343 (17) | −1.11034 (18) | −0.25097 (13) | 0.0863 (6) | |
C1 | −0.2022 (2) | −1.0212 (2) | −0.39161 (15) | 0.0614 (7) | |
C2 | −0.2759 (2) | −1.0701 (3) | −0.45469 (17) | 0.0702 (7) | |
C3 | −0.2670 (2) | −1.0289 (3) | −0.53221 (16) | 0.0723 (7) | |
C4 | −0.1846 (2) | −0.9361 (3) | −0.54869 (15) | 0.0653 (7) | |
C4a | −0.11190 (19) | −0.8851 (2) | −0.48594 (13) | 0.0506 (6) | |
C4b | −0.0220 (2) | −0.7845 (2) | −0.48720 (14) | 0.0532 (6) | |
C5 | 0.0122 (2) | −0.7134 (3) | −0.55244 (16) | 0.0714 (7) | |
C6 | 0.0997 (3) | −0.6225 (3) | −0.54009 (18) | 0.0825 (9) | |
C7 | 0.1534 (3) | −0.6026 (3) | −0.46414 (19) | 0.0839 (9) | |
C8 | 0.1208 (2) | −0.6735 (3) | −0.39891 (17) | 0.0725 (7) | |
C8a | 0.0296 (2) | −0.7640 (2) | −0.40863 (14) | 0.0539 (6) | |
C9 | −0.02719 (19) | −0.8556 (2) | −0.35357 (13) | 0.0493 (6) | |
C9a | −0.11783 (19) | −0.9285 (2) | −0.40658 (13) | 0.0489 (6) | |
C10 | −0.0060 (2) | −0.8737 (2) | −0.27363 (14) | 0.0531 (6) | |
C11 | −0.0221 (2) | −1.0863 (2) | −0.22611 (14) | 0.0604 (7) | |
C12 | −0.0955 (2) | −1.1787 (3) | −0.17876 (16) | 0.0688 (7) | |
C13 | −0.1308 (5) | −1.2902 (3) | −0.2346 (2) | 0.1435 (18) | |
C14 | −0.2080 (3) | −1.1203 (3) | −0.1491 (2) | 0.1080 (12) | |
C15 | −0.0162 (4) | −1.2248 (4) | −0.1072 (3) | 0.1449 (18) | |
C16 | 0.0764 (2) | −0.8021 (3) | −0.21199 (15) | 0.0667 (7) | |
C17 | 0.0594 (3) | −0.8474 (3) | −0.12516 (17) | 0.0990 (11) | |
C18 | 0.2096 (2) | −0.8281 (3) | −0.22818 (19) | 0.0893 (9) | |
C19 | 0.0433 (3) | −0.6589 (3) | −0.21374 (18) | 0.0888 (9) | |
H1 | −0.2094 | −1.0505 | −0.3394 | 0.074* | |
H2 | −0.3326 | −1.1321 | −0.4442 | 0.084* | |
H3 | −0.3168 | −1.0637 | −0.5738 | 0.087* | |
H4 | −0.1779 | −0.9081 | −0.6013 | 0.078* | |
H5 | −0.0240 | −0.7276 | −0.6038 | 0.086* | |
H6 | 0.1230 | −0.5739 | −0.5832 | 0.099* | |
H7 | 0.2128 | −0.5404 | −0.4565 | 0.101* | |
H8 | 0.1600 | −0.6605 | −0.3483 | 0.087* | |
H13a | −0.1818 | −1.3480 | −0.2077 | 0.215* | |
H13b | −0.0596 | −1.3344 | −0.2486 | 0.215* | |
H13c | −0.1733 | −1.2584 | −0.2827 | 0.215* | |
H14a | −0.2599 | −1.0926 | −0.1943 | 0.162* | |
H14b | −0.1867 | −1.0482 | −0.1152 | 0.162* | |
H14c | −0.2492 | −1.1827 | −0.1187 | 0.162* | |
H15a | −0.0602 | −1.2846 | −0.0767 | 0.217* | |
H15b | 0.0080 | −1.1533 | −0.0737 | 0.217* | |
H15c | 0.0540 | −1.2658 | −0.1257 | 0.217* | |
H17a | −0.0236 | −0.8384 | −0.1139 | 0.148* | |
H17b | 0.1087 | −0.7965 | −0.0878 | 0.148* | |
H17c | 0.0828 | −0.9355 | −0.1197 | 0.148* | |
H18a | 0.2304 | −0.9140 | −0.2125 | 0.134* | |
H18b | 0.2606 | −0.7692 | −0.1975 | 0.134* | |
H18c | 0.2203 | −0.8171 | −0.2846 | 0.134* | |
H19a | 0.0354 | −0.6297 | −0.2686 | 0.133* | |
H19b | 0.1056 | −0.6111 | −0.1844 | 0.133* | |
H19c | −0.0316 | −0.6467 | −0.1894 | 0.133* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.0550 (9) | 0.0568 (10) | 0.0514 (9) | 0.0031 (8) | 0.0090 (7) | 0.0059 (7) |
O2 | 0.0751 (12) | 0.0803 (13) | 0.1077 (15) | 0.0211 (11) | 0.0376 (11) | 0.0208 (11) |
C1 | 0.0666 (16) | 0.0596 (15) | 0.0583 (15) | −0.0078 (13) | 0.0059 (12) | 0.0020 (12) |
C2 | 0.0697 (17) | 0.0651 (17) | 0.0751 (18) | −0.0168 (13) | 0.0007 (14) | −0.0015 (14) |
C3 | 0.0712 (17) | 0.0804 (19) | 0.0637 (17) | −0.0082 (16) | −0.0079 (13) | −0.0042 (15) |
C4 | 0.0685 (16) | 0.0742 (17) | 0.0521 (14) | 0.0015 (15) | −0.0027 (12) | 0.0044 (13) |
C4a | 0.0506 (13) | 0.0511 (13) | 0.0503 (14) | 0.0083 (11) | 0.0043 (10) | 0.0002 (11) |
C4b | 0.0522 (13) | 0.0517 (14) | 0.0563 (15) | 0.0053 (11) | 0.0085 (11) | 0.0033 (11) |
C5 | 0.0798 (18) | 0.0733 (18) | 0.0617 (16) | −0.0046 (15) | 0.0093 (14) | 0.0113 (14) |
C6 | 0.096 (2) | 0.0776 (19) | 0.076 (2) | −0.0152 (18) | 0.0180 (17) | 0.0204 (16) |
C7 | 0.091 (2) | 0.0726 (19) | 0.090 (2) | −0.0280 (16) | 0.0166 (17) | 0.0048 (17) |
C8 | 0.0834 (18) | 0.0679 (17) | 0.0663 (17) | −0.0174 (15) | 0.0063 (14) | −0.0017 (14) |
C8a | 0.0553 (14) | 0.0495 (13) | 0.0574 (14) | −0.0016 (11) | 0.0080 (11) | −0.0005 (11) |
C9 | 0.0511 (13) | 0.0482 (13) | 0.0487 (13) | 0.0018 (11) | 0.0045 (10) | −0.0009 (10) |
C9a | 0.0490 (13) | 0.0455 (13) | 0.0522 (13) | 0.0025 (10) | 0.0043 (10) | −0.0009 (10) |
C10 | 0.0500 (13) | 0.0543 (14) | 0.0552 (14) | −0.0011 (11) | 0.0058 (11) | −0.0009 (11) |
C11 | 0.0623 (16) | 0.0621 (16) | 0.0577 (15) | 0.0074 (13) | 0.0103 (12) | 0.0043 (12) |
C12 | 0.0775 (18) | 0.0687 (17) | 0.0619 (16) | 0.0042 (14) | 0.0175 (13) | 0.0131 (14) |
C13 | 0.237 (5) | 0.078 (2) | 0.125 (3) | −0.052 (3) | 0.080 (3) | −0.009 (2) |
C14 | 0.098 (2) | 0.102 (2) | 0.131 (3) | −0.003 (2) | 0.057 (2) | 0.024 (2) |
C15 | 0.123 (3) | 0.181 (4) | 0.131 (3) | 0.012 (3) | 0.012 (3) | 0.094 (3) |
C16 | 0.0684 (16) | 0.0749 (18) | 0.0555 (15) | −0.0093 (14) | −0.0046 (12) | −0.0033 (13) |
C17 | 0.118 (3) | 0.120 (3) | 0.0560 (18) | −0.028 (2) | −0.0086 (16) | −0.0042 (18) |
C18 | 0.0679 (18) | 0.099 (2) | 0.099 (2) | −0.0127 (17) | −0.0129 (16) | 0.0041 (18) |
C19 | 0.107 (2) | 0.081 (2) | 0.078 (2) | −0.0122 (18) | 0.0004 (17) | −0.0214 (16) |
Geometric parameters (Å, º) top
O1—C11 | 1.358 (3) | C1—H1 | 0.9300 |
O1—C10 | 1.420 (3) | C2—H2 | 0.9300 |
O2—C11 | 1.194 (3) | C3—H3 | 0.9300 |
C1—C2 | 1.384 (3) | C4—H4 | 0.9300 |
C1—C9a | 1.384 (3) | C5—H5 | 0.9300 |
C2—C3 | 1.369 (4) | C6—H6 | 0.9300 |
C3—C4 | 1.375 (4) | C7—H7 | 0.9300 |
C4—C4a | 1.383 (3) | C8—H8 | 0.9300 |
C4a—C9a | 1.401 (3) | C13—H13a | 0.9600 |
C4a—C4b | 1.453 (3) | C13—H13b | 0.9600 |
C4b—C5 | 1.389 (3) | C13—H13c | 0.9600 |
C4b—C8a | 1.407 (3) | C14—H14a | 0.9600 |
C5—C6 | 1.366 (4) | C14—H14b | 0.9600 |
C6—C7 | 1.375 (4) | C14—H14c | 0.9600 |
C7—C8 | 1.383 (4) | C15—H15a | 0.9600 |
C8—C8a | 1.388 (3) | C15—H15b | 0.9600 |
C8a—C9 | 1.495 (3) | C15—H15c | 0.9600 |
C9—C10 | 1.347 (3) | C17—H17a | 0.9600 |
C9—C9a | 1.501 (3) | C17—H17b | 0.9600 |
C10—C16 | 1.524 (3) | C17—H17c | 0.9600 |
C11—C12 | 1.519 (3) | C18—H18a | 0.9600 |
C12—C14 | 1.507 (4) | C18—H18b | 0.9600 |
C12—C15 | 1.511 (4) | C18—H18c | 0.9600 |
C12—C13 | 1.526 (5) | C19—H19a | 0.9600 |
C16—C19 | 1.542 (4) | C19—H19b | 0.9600 |
C16—C17 | 1.543 (4) | C19—H19c | 0.9600 |
C16—C18 | 1.548 (4) | | |
| | | |
C8a—C9—C10 | 129.9 (2) | C4—C3—H3 | 119.9 |
C9a—C9—C10 | 125.0 (2) | C3—C4—H4 | 120.5 |
C9—C10—C16 | 130.6 (2) | C4a—C4—H4 | 120.5 |
C9—C10—O1 | 116.46 (19) | C6—C5—H5 | 120.5 |
C18—C16—C19 | 113.4 (2) | C4b—C5—H5 | 120.5 |
C17—C16—C19 | 105.8 (2) | C5—C6—H6 | 119.9 |
C17—C16—C18 | 106.8 (2) | C7—C6—H6 | 119.9 |
C10—C16—C17 | 111.8 (2) | C6—C7—H7 | 119.4 |
C10—C16—C18 | 109.6 (2) | C8—C7—H7 | 119.4 |
C10—C16—C19 | 109.5 (2) | C7—C8—H8 | 119.9 |
C13—C12—C14 | 108.9 (3) | C8a—C8—H8 | 119.9 |
C15—C12—C14 | 108.9 (3) | C12—C13—H13b | 109.5 |
C15—C12—C13 | 110.3 (3) | C12—C13—H13a | 109.5 |
C11—O1—C10 | 117.24 (17) | H13a—C13—H13b | 109.5 |
C2—C1—C9a | 119.8 (2) | C12—C13—H13c | 109.5 |
C3—C2—C1 | 121.3 (2) | H13a—C13—H13c | 109.5 |
C2—C3—C4 | 120.1 (2) | H13b—C13—H13c | 109.5 |
C3—C4—C4a | 119.0 (2) | C12—C14—H14a | 109.5 |
C4—C4a—C9a | 121.5 (2) | C12—C14—H14b | 109.5 |
C4—C4a—C4b | 129.5 (2) | H14a—C14—H14b | 109.5 |
C9a—C4a—C4b | 108.99 (19) | C12—C14—H14c | 109.5 |
C5—C4b—C8a | 121.9 (2) | H14a—C14—H14c | 109.5 |
C5—C4b—C4a | 128.6 (2) | H14b—C14—H14c | 109.5 |
C8a—C4b—C4a | 109.52 (19) | C12—C15—H15a | 109.5 |
C6—C5—C4b | 119.0 (3) | C12—C15—H15b | 109.5 |
C5—C6—C7 | 120.2 (3) | H15a—C15—H15b | 109.5 |
C6—C7—C8 | 121.2 (3) | C12—C15—H15c | 109.5 |
C7—C8—C8a | 120.2 (3) | H15a—C15—H15c | 109.5 |
C8—C8a—C4b | 117.4 (2) | H15b—C15—H15c | 109.5 |
C8—C8a—C9 | 134.6 (2) | C16—C17—H17a | 109.5 |
C4b—C8a—C9 | 107.97 (19) | C16—C17—H17b | 109.5 |
C8a—C9—C9a | 105.13 (18) | H17a—C17—H17b | 109.5 |
C1—C9a—C4a | 118.2 (2) | C16—C17—H17c | 109.5 |
C1—C9a—C9 | 133.4 (2) | H17a—C17—H17c | 109.5 |
C4a—C9a—C9 | 108.38 (19) | H17b—C17—H17c | 109.5 |
O1—C10—C16 | 112.84 (19) | C16—C18—H18a | 109.5 |
O2—C11—O1 | 121.5 (2) | C16—C18—H18b | 109.5 |
O2—C11—C12 | 124.6 (2) | H18a—C18—H18b | 109.5 |
O1—C11—C12 | 113.8 (2) | C16—C18—H18c | 109.5 |
C14—C12—C11 | 113.6 (2) | H18a—C18—H18c | 109.5 |
C15—C12—C11 | 107.8 (2) | H18b—C18—H18c | 109.5 |
C11—C12—C13 | 107.2 (2) | C16—C19—H19a | 109.5 |
C2—C1—H1 | 120.1 | C16—C19—H19b | 109.5 |
C9a—C1—H1 | 120.1 | H19a—C19—H19b | 109.5 |
C3—C2—H2 | 119.3 | C16—C19—H19c | 109.5 |
C1—C2—H2 | 119.3 | H19a—C19—H19c | 109.5 |
C2—C3—H3 | 119.9 | H19b—C19—H19c | 109.5 |
| | | |
C8a—C9—C10—C16 | 4.3 (4) | C8—C8a—C9—C10 | 2.3 (4) |
C9a—C9—C10—O1 | 0.6 (3) | C4b—C8a—C9—C10 | 178.8 (2) |
C9a—C9—C10—C16 | −175.6 (2) | C4b—C8a—C9—C9a | −1.3 (2) |
C8a—C9—C10—O1 | −179.4 (2) | C2—C1—C9a—C4a | 1.4 (3) |
C8—C8a—C9—C9a | −177.8 (3) | C4—C4a—C9a—C1 | −2.5 (3) |
C8a—C9—C9a—C1 | −176.5 (2) | C4b—C4a—C9a—C1 | 177.3 (2) |
C2—C1—C9a—C9 | 179.1 (2) | C4—C4a—C9a—C9 | 179.3 (2) |
C9a—C1—C2—C3 | 0.2 (4) | C4b—C4a—C9a—C9 | −1.0 (2) |
C1—C2—C3—C4 | −0.7 (4) | C10—C9—C9a—C1 | 3.5 (4) |
C2—C3—C4—C4a | −0.3 (4) | C10—C9—C9a—C4a | −178.7 (2) |
C3—C4—C4a—C9a | 2.0 (4) | C8a—C9—C9a—C4a | 1.4 (2) |
C3—C4—C4a—C4b | −177.7 (2) | C11—O1—C10—C9 | 98.2 (2) |
C4—C4a—C4b—C5 | 0.8 (4) | C11—O1—C10—C16 | −84.9 (2) |
C9a—C4a—C4b—C5 | −178.9 (2) | C10—O1—C11—O2 | −7.0 (3) |
C4—C4a—C4b—C8a | 179.9 (2) | C10—O1—C11—C12 | 172.8 (2) |
C9a—C4a—C4b—C8a | 0.1 (2) | O2—C11—C12—C14 | 175.4 (3) |
C8a—C4b—C5—C6 | 1.1 (4) | O1—C11—C12—C14 | −4.4 (3) |
C4a—C4b—C5—C6 | −180.0 (2) | O2—C11—C12—C15 | 54.6 (4) |
C4b—C5—C6—C7 | 0.4 (4) | O1—C11—C12—C15 | −125.2 (3) |
C5—C6—C7—C8 | 0.1 (5) | O2—C11—C12—C13 | −64.2 (4) |
C6—C7—C8—C8a | −2.1 (5) | O1—C11—C12—C13 | 116.0 (3) |
C7—C8—C8a—C4b | 3.4 (4) | C9—C10—C16—C19 | 56.3 (3) |
C7—C8—C8a—C9 | 179.6 (3) | O1—C10—C16—C19 | −120.0 (2) |
C5—C4b—C8a—C8 | −2.9 (3) | C9—C10—C16—C17 | 173.2 (3) |
C4a—C4b—C8a—C8 | 177.9 (2) | O1—C10—C16—C17 | −3.2 (3) |
C5—C4b—C8a—C9 | 179.9 (2) | C9—C10—C16—C18 | −68.6 (3) |
C4a—C4b—C8a—C9 | 0.7 (2) | O1—C10—C16—C18 | 115.0 (2) |
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