What structure is equivalent to Compound 1 (shown below)?

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11ecba2d_1282_81fb_a3bf_2784f9918bc6_MD0008_00 To determine whether chiral molecules with the same four substituents on the central carbon are identical, the configuration of the stereocenter must be considered. First, the substituent priority is determined, and then R or S is assigned to each stereocenter. If the structure is shown with the lowest-priority group (usually hydrogen) pointing away from the viewer (dash) and priorities 1-2-3 follow a clockwise progression, the compound has an R configuration. (Priorities 1-2-3 following a counterclockwise progression indicate an S configuration.) Alternatively, if the structure is shown with the lowest-priority group pointing toward the viewer (wedge), the compound is being viewed from the opposite perspective. If priorities 1-2-3 follow a clockwise progression in this case, the compound has an S configuration. If two compounds with the same four substituents also have the same stereocenter configuration, they are the same compound. The priority of the substituents on Compound 1 is (highest to lowest): OH, CH₂Cl, CH₃, and H. The lowest-priority group is away from the viewer, and priorities 1-2-3 follow a clockwise progression, indicating an R configuration. The correct answer also has an R configuration. It can also be rotated 90° to the left to put the substituents in the same position as Compound 1. (Choices A, C, and D) These structures are enantiomers of Compound 1. They have the same four substituents but in an S configuration (opposite that of Compound 1). They are not identical to Compound 1, but are identical to one another. Educational objective: Chiral compounds with the same four substituents on the central carbon are identical if they have the same stereochemical configuration. When the lowest-priority substituent is pointing away from the viewer, an R configuration is present if the substituent priorities follow a clockwise progression, whereas a counterclockwise progression indicates an S configuration. If the lowest-priority substituent is pointing toward the viewer, an R configuration is indicated by substituent priorities following a counterclockwise progression.

What Structure Is Equivalent to Compound 1 (Shown Below)