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Solutions to Problems 259 0 You need to connect the end carbon of one propene with the middle carbon of the other, you need to functionalize accordingly. MgCl HCI Mg, (CH₃CH₂)₂O CH₃CHCH₃ 1. THF CH₃CH=CH₂ CH₃CH₂CH₂OH PCC, CH₃CH₂CH OH product CH₂Cl₂ CI (b) Analysis: The final product can come from reaction of a suitable reagent such as with 4-heptanol. This, in turn. can come from a Grignard synthesis. Here is an outline of the retrosynthetic plan. OH + a b OH As mentioned. the synthesis ends easily enough: changing the OH of 4-heptanol to with To form bonds "a" and "b", you must make That will require an anti-Markovnikov addition to propene. Working bond "a" is addition of this Grignard to an aldehyde. Where does the aldehyde come from? It must be from oxidation of a primary alcohol with PCC. The alcohol then comes from formation of bond "b" from addition of the same Grignard to formaldehyde. So you have CH₃CH=CH₂ peroxide CH₃CH₂CH₃Br Mg.(CH₃CH₂)₂O first: then. CH₃CH₂CH₂CHO 1. (CH₃CH₂)₂O product OH