Treatment with sodium borohydride converts aldosterone A in to an optically inactive alditol. Ruff degradation of A from B, whose alditol is optically inactive. Ruff degradation of B from D - glycerol dehydration. Identify A and B. Please help urgently. Please!!!!!

To identify compounds A and B in this problem, we need to follow the given reactions and conversion steps:

1. Treatment with sodium borohydride converts aldosterone A into an optically inactive alditol.
2. Ruff degradation of A gives compound B, whose alditol is also optically inactive.
3. Ruff degradation of B occurs through glycerol dehydration, resulting in compound D.

Based on these reactions, we can work backward to determine the identity of A and B.

Starting with compound D, we know it is obtained from the Ruff degradation of B through glycerol dehydration. Glycerol dehydration involves the elimination of water from glycerol, resulting in an unsaturated compound. In this case, compound D is the product of this reaction. Therefore, compound B is glycerol (or also known as propane-1,2,3-triol).

Moving on to compound B, we know that its Ruff degradation results in an optically inactive alditol. An alditol is a sugar alcohol, and in this case, it is optically inactive, meaning it does not rotate plane-polarized light. One common optically inactive alditol is meso-erythritol, which is a four-carbon sugar alcohol. Hence, compound B is meso-erythritol.

Now, let's focus on compound A, which is the starting material converted to an optically inactive alditol. Since compound A is converted into meso-erythritol (B) through treatment with sodium borohydride, compound A must be the aldehyde or ketone derivative of meso-erythritol. The aldehyde derivative of meso-erythritol is called erythrose, while the ketone derivative is called erythrulose.

In conclusion, compound A is either erythrose or erythrulose, and compound B is meso-erythritol.