Which of the following methods yield saturated hydrocarbon ?

Options

A. `R-CH=CH_2underset(CH_3COOH)overset(BH_3)to`
B. `R-CH=CH_2overset(CH_2N_2,Delta)to`
C.
D.

Explanation

To determine which of the following methods yield saturated hydrocarbons, we will analyze each option step by step.

### Step 1: Analyze the first method
- **Reaction**: RCH=CH2 + BH3 + CH3COOH
- **Process**: The presence of BH3 (Boron Hydride) in the reaction with an alkene (RCH=CH2) and acetic acid (CH3COOH) leads to hydroboration. This process adds across the double bond, resulting in the formation of a saturated hydrocarbon.
- **Product**: The product formed is CH2-CH3, which is an alkane (saturated hydrocarbon).

### Step 2: Analyze the second method
- **Reaction**: CH2N2 (Diazomethane) on heating
- **Process**: When CH2N2 is heated, it decomposes to form CH2 and nitrogen gas (N2). The CH2 can then react with another alkene (like CH2=CH2) to form a cyclopropane ring.
- **Product**: The product formed is a cyclopropane, which is also a saturated hydrocarbon.

### Step 3: Analyze the third method
- **Reaction**: Na + ether with an alkene
- **Process**: The presence of sodium in ether can lead to the formation of a cyclopentane ring through a coupling reaction.
- **Product**: The product formed is cyclopentane, which is a saturated hydrocarbon.

### Step 4: Analyze the fourth method
- **Reaction**: NaOH + CaO (heating) with a cycloalkane
- **Process**: When a cycloalkane undergoes a reaction with NaOH and CaO under heating, it can lead to the removal of CO2 and the formation of a cyclohexane ring.
- **Product**: The product formed is cyclohexane, which is also a saturated hydrocarbon.

### Conclusion
All four methods yield saturated hydrocarbons. Therefore, the answer is that all options (1, 2, 3, and 4) yield saturated hydrocarbons.

---