Chem E2a-Lecture 6-Annotated-2013

10b cleavage of ethers ethers are generally inert

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: actions: Br HO OH NaOH NaOH Cl 9 Reading: Section 7.10b Synthesis of Ethers: Routes Involving Carboca:ons   Write curved-arrow mechanisms for the synthesis of the following ether: O CH3 Desired Product Option 1: Alkene Addition Option 2: SN1 10 Reading: Section 7.10b Cleavage of Ethers •  Ethers are generally inert under most reaction conditions; they are often used as solvents. However, ethers can be cleaved under certain forcing conditions. Draw curved-arrow mechanisms for the following reactions: O conc. HBr Br Br O conc. Hl I 11 + HO Reading: Section 7.4f Sulfur As Nucleophile •  The SN2 reactions of thiolates lead to thiols and sulfides: NaOH R1 SH R1 S R2 LG R1 a thiolate R2 + S LG a sulfide •  The sulfur of a sulfide (“thioether”) is a reasonably good nucleophile -- much better than the oxygen of an ether. Thus, sulfides can be SN2 nucleophiles. The resulting products are called sulfonium salts: R1 S R2 + R3 R1 Br S R2 + Br R3 a sulfide a sulfonium salt •  Sulfonium salts are excellent electrophiles. They can act as alkylating agents. For example: 12 Reading: Section 7.10a Sulfur in Biology •  Sulfur is a very...
View Full Document

This document was uploaded on 01/29/2014.

Ask a homework question - tutors are online