Question

Apply the Skill 12.15 Extracts from the flowering plants of Asteraceae have been used to produce medicine, rubber, and pesticides. (+)-Canssone, a compound isolated from such extracts, has been found to have antibacterial propertiles. During a synthesis of ()-carissone, a Grignard reaction was used to convert compound 1 into compound 2, as shown below. Oxidation (Section 12.10) (+)-Carissone

Please draw the complete mechanism with lone pairs and charges.

Answer 1

Extracts from the flowering plants of Asteracese have been used to produced medicine, rubber, and pestiodes. (+)-Carissone, a compound isolated from such extracts, has been found to have antibacterial properties. During a synthesis of (1) carissone, a Grignard reaction was used to convert compound 1 into compound 2, as shown below. In the given question from compound 1 to compound 2, an ester functional group get into tertiary alcohol group. Ester on reaction with two equivalents of Grignard reagent forms tertiary alcohols In the first step ester on reaction with first equivalent of methyl magnesium bromide (Grignard reagent) gives the ketone product. The formed ketone is more reactive than that of the starting ester. Ketone on reaction with second equivalent of Grignard reagent gives the tertiary alcohol product.