Which are the correct statements ?

Options

A. trans `-` or `E-`cyclooctene is not a flat molecule and has two puckered conformations which are isolable enantiomers.
B. trans `-` or `E-`cyclooctene is achiral and is a flat molecule devoid of chirality.
C. trans `-` or `E-`cyclodecene is a chiral molecule.
D. trans `-` or `E-`cyclodecene is an achiral and a flat molecule devoid of chirality.

Explanation

To determine which statements about trans or e-cyclooctane are correct, let's analyze each option step by step.

### Step 1: Analyze Option A
**Statement:** Trans or e-cyclooctane is not a flat molecule and has two puckered conformations which are isolable enantiomers.

**Analysis:**
- Trans-cyclooctene is indeed not a flat molecule. It adopts a puckered conformation to minimize steric strain.
- The two puckered forms can exist as enantiomers, meaning they are non-superimposable mirror images of each other.

**Conclusion:** This statement is **correct**.

### Step 2: Analyze Option B
**Statement:** Trans or e-cyclooctane is achiral and is a flat molecule devoid of chirality.

**Analysis:**
- While trans-cyclooctene is achiral, it is not a flat molecule. As established, it has a puckered structure.

**Conclusion:** This statement is **incorrect**.

### Step 3: Analyze Option C
**Statement:** Trans or e-cyclooctane is a chiral molecule.

**Analysis:**
- Trans-cyclooctene is not chiral due to its symmetrical structure. It does not possess a chiral center.

**Conclusion:** This statement is **incorrect**.

### Step 4: Analyze Option D
**Statement:** Trans or e-cyclodecane is achiral and a flat molecule devoid of chirality.

**Analysis:**
- Trans-cyclodecane is indeed achiral and can be considered a flat molecule. It does not have any chiral centers.

**Conclusion:** This statement is **correct**.

### Final Summary
The correct statements are:
- **Option A:** Correct
- **Option D:** Correct