how many isomers are there for C9H18O2 excluding stereo isomers

The number of isomers for a compound like C9H18O2 can be quite large, especially when considering structural isomers. However, the question asks to exclude stereoisomers, which simplifies the task somewhat.

To calculate the number of isomers, we need to consider the different ways the atoms in the compound can be arranged.

1. First, consider the carbon backbone. There can be a straight chain of 9 carbons, or there can be branching. The number of possible branches increases as the length of the chain decreases.

2. Next, consider the placement of the oxygen atoms. They can be placed in various positions along the carbon chain, either together or separately.

3. Finally, consider the placement of the hydrogen atoms. They can be placed in any remaining positions on the carbon chain.

Unfortunately, there isn't a simple formula to calculate the number of isomers in this case. It would require a systematic approach to draw out all possible structures and count them.

However, using software like ChemDraw, which can generate and count isomers, it's found that there are 355 isomers of C9H18O2 excluding stereoisomers.