Question

Devising a 5-Step Synthesis of Thiol from Allyl Halide:

a) What is the first step in the synthesis of thiol from allyl halide?
b) Which reagent is used in the second step of the synthesis?
c) In the third step, what type of reaction occurs?
d) What is the final product obtained in the fifth step?

Answer 1

The first step in the synthesis is the addition of ethylmagnesium bromide to the allyl halide. The second step involves a Heck coupling reaction. The final product is a thiol.

Step-by-step explanation:

To devise a 5-step synthesis of thiol from allyl halide, the first step is the addition of ethylmagnesium bromide (EtMgBr) to the allyl halide. This reaction forms an alkyl magnesium bromide intermediate.

In the second step, 3-tributyltin-2-chloropyridine, Pd(PPh3)4, and Cu(I) Br are used as reagents to perform a Heck coupling reaction. This reaction replaces the halide with a new functional group.

The third step involves a reaction with hydrazine and TiCl3 for one compound and a reaction with concentrated acetic acid for another compound.

The final product obtained in the fifth step is a thiol, specifically C4H9-SH.