◇ vs. STR 2C

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(2C)- X   D or H+S
      2D  H or S+C
      2H  S or C+D
      2S  C or D+H
      2N  C+H or D+S
      3C+ PRE

(2C)-P-(2D)- X   H or S+C
             2H  S or C+D
             2S  C or D+H
             2N  C+H or D+S
             3C  D or H+S
             3D+ the same, PRE

(2C)-P-(2H)- rationale the same above