Compound 1 is shown below. All of the following are equivalent to Compound 1 EXCEPT:

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Quizplus · Accepted Answer

11ecba2d_128a_223c_a3bf_0dcf0bb887fb_MD0008_00 Compounds can be illustrated in different ways and orientations. Molecules must have all substituents in the same relative position and stereochemical orientation to be considered the same compound. The cyclohexane ring, for example, can be depicted using the wedge-dash projection or a chair conformation. In the wedge-dash projection, the wedges indicate that the substituent is above or in front of the plane of the ring, and the dashes indicate that the substituent is below or behind the plane. In a chair conformation, the wedges and dashes can be shown as axial or equatorial positions. The axial positions are perpendicular to the plane of the ring and alternate pointing above or below the ring plane. The equatorial positions are oriented radially with the ring plane and alternate positions slightly above or below the plane. Compound 1 is a six-membered ring shown in the wedge-dash projection with three substituents: −OH, −Br, and −CH₃. The −OH group is bonded to carbon shown by a wedge, and −Br and −CH₃ are bonded to carbon atoms shown by dashed lines. If the carbon atoms are numbered 1-6, beginning at the carbon bonded to −OH and continuing clockwise, −Br is on carbon 3 and −CH₃ is on carbon 5. The answer choices are chair conformations and must maintain the positions and stereochemical orientations of Compound 1 to be considered the same molecule. The chair conformations that depict −OH above the plane of the ring ("up") and −Br and −CH₃ below the plane ("down") and on carbons 3 and 5 clockwise from −OH, respectively, are the same molecule as Compound 1 (Choices A, B, and C). The −OH substituent is equatorial "down" and the −Br and −CH₃ substituents are axial "up" in this chair conformation, causing the stereochemical orientation in this structure to be the complete opposite of Compound 1. Therefore, these structures are different compounds and considered enantiomers. Educational objective: Compounds can be illustrated in different orientations and forms, including wedge-dash projections and chair conformations. For two depictions of a molecule to be considered the same compound, the atoms must have the same relative position and stereochemical orientation.

Compound 1 Is Shown Below