File size: 5,109 Bytes
606deef | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 | {
"problem_id": "Exam-07-T10",
"header": "The Remarkable Role of LiCl",
"header_images": [],
"subquestions": [
{
"sub_id": "Exam-07-T10-1",
"tags": [
"2.4"
],
"text_open": "10.1.1 Write the SMILES representation of the reaction product, given that the product contains 1 fewer carbon atom than the reactant.",
"text_images": [
{
"file": "Exam-07-T10-1-1-prompt.png",
"description": "'COC(C=C1)=CC=C1C2=CC=C(OC)N=C2' is reacted under LiCl/DMF conditions with microwave irradiation."
}
],
"full_mark": 2,
"rubric": [
"'O=C1C=CC(C2=CC=C(OC)C=C2)=CN1' (2 points)"
],
"rubric_images": [
{
"file": "Exam-07-T10-1-1-rubric.png",
"description": "'O=C1C=CC(C2=CC=C(OC)C=C2)=CN1'"
}
]
},
{
"sub_id": "Exam-07-T10-2",
"tags": [
"2.4",
"2.2"
],
"text_open": "10.1.2 Based on 10.1.1, write the SMILES representation of the reaction product and the SMILES representation of 1 key intermediate that illustrates the role of LiCl, given that the product contains 1 fewer carbon atom than the reactant.",
"text_images": [
{
"file": "Exam-07-T10-2-1-prompt.png",
"description": "'COC1=C(OC)C=C(C=O)C=C1' is reacted under LiCl/DMF conditions with microwave irradiation."
}
],
"full_mark": 4,
"rubric": [
"Product: 'OC1=C(OC)C=C(C=O)C=C1' (2 points)",
"Intermediate: '[Cl-].[Li+].O=CC1=CC(OC)=C(OC)C=C1', in which the Li ion is coordinated simultaneously by the O atoms of the two methoxy groups and by Cl^-, giving a three-coordinate geometry. (2 points)"
],
"rubric_images": [
{
"file": "Exam-07-T10-2-1-rubric.png",
"description": "'OC1=C(OC)C=C(C=O)C=C1'"
},
{
"file": "Exam-07-T10-2-2-rubric.png",
"description": "Intermediate: the two ether O atoms coordinate to Li to form the complex '[Cl-].[Li+].O=CC1=CC(OC)=C(OC)C=C1'"
}
]
},
{
"sub_id": "Exam-07-T10-3",
"tags": [
"2.4",
"1.2",
"2.8"
],
"text_open": "10.1.3 The starting material is an optically active chiral ester. Write the SMILES representation of the reaction product. State the advantage of this method over methods such as hydrolysis with a strong base.",
"text_images": [
{
"file": "Exam-07-T10-3-1-prompt.png",
"description": "'O=C([C@@H](C1=CC2=CC=C(C=C2C=C1)OC)C)OC' is reacted under LiCl/DMF conditions with microwave irradiation."
}
],
"full_mark": 4,
"rubric": [
"'OC([C@H](C)C1=CC2=CC=C(OC)C=C2C=C1)=O' (2 points)",
"The configuration at the α stereocenter is retained without racemization. (2 points)"
],
"rubric_images": [
{
"file": "Exam-07-T10-3-1-rubric.png",
"description": "'OC([C@H](C)C1=CC2=CC=C(OC)C=C2C=C1)=O'"
}
]
},
{
"sub_id": "Exam-07-T10-4",
"tags": [
"2.2",
"2.3"
],
"text_open": "10.2 The following reaction proceeds through a radical process, in which the fluorinating reagent is a single-electron oxidant.\n 10.2.1 Write the SMILES representations of 1 key intermediate associated with the fluorinating reagent and 2 key radical intermediates that contain no halogen atoms and only one six-membered ring.",
"text_images": [
{
"file": "Exam-07-T10-4-1-prompt.png",
"description": "'NC1=CC=CC=N1' and 'ClC[N+]12CC[N+](CC2)(F)CC1' · $2\\text{BF}_4^{-}$) react under LiCl/DMF conditions to give the product with the SMILES representation 'NC1=CC=C(Cl)C=N1'."
}
],
"full_mark": 6,
"rubric": [
"'ClC[N+]1(CC2)CC[N+]2CC1' (note: a nitrogen-centered radical cation) · $\\text{BF}_4^{-}\\text{F}^{-}$ (2 points).",
"'NC1=C[CH+][C]C=N1' (2 points).",
"'N=C1C=C[C]C=N1' (2 points)"
],
"rubric_images": [
{
"file": "Exam-07-T10-4-1-rubric.png",
"description": "'ClC[N+]1(CC2)CC[N+]2CC1' (note: a nitrogen-centered radical cation) · $\\text{BF}_4^{-}\\text{F}^{-}$"
},
{
"file": "Exam-07-T10-4-2-rubric.png",
"description": "'NC1=C[CH+][C]C=N1'."
},
{
"file": "Exam-07-T10-4-3-rubric.png",
"description": "'N=C1C=C[C]C=N1'"
}
]
},
{
"sub_id": "Exam-07-T10-5",
"tags": [
"2.4"
],
"text_open": "10.2.2 Write all by-products of the reaction; give the SMILES representation for the organic product.",
"text_images": [],
"full_mark": 6,
"rubric": [
"'ClC[N+]1(CC2)CCN2CC1' · $\\text{BF}_4^{-}$ (2 points)",
"HF (2 points)",
"$LiBF_4$ (2 points)"
],
"rubric_images": [
{
"file": "Exam-07-T10-5-1-rubric.png",
"description": "'ClC[N+]1(CC2)CCN2CC1' · $\\text{BF}_4^{-}$"
}
]
}
]
}
|