This preview shows page 1. Sign up to view the full content.
Unformatted text preview: 1 4-33 continued HO
(j ) ( k) �
H o ( I) �
Br OH (n) CH3 ry."OCH3 �1 I 0H (a) On long-term exposure to air , ethers form peroxides. Pero xides are explosive when concentrated or heated. (For exactly this reason, ethers should n ever be distilled to dryness. ) (b ) Peroxide formation can be prevented by excluding oxygen. Ethers can be checked for the presence of peroxides, and peroxides can be destroyed safely by treatment with reducing a gents . (a ) Beginning with (R)-butan-2-o l and producing the (R) sulfide requires two inversions of configuration. H Br HO H
1 4-35 1 4-34 �
5 (b) Synthesis of the (5) isomer directly requires only one inversion . HO H An a lternative approach would be to make the tosylate, displace with chloride or bromide (SN2 with inversion ) , then do a second inversion with Na SCH3. Ts O H R � R T sCI pyridine �
.-. 1 4-36 (a )
� ......,., molecular ion mlz 1 02 mlz 73 ))� }
" C H2 3 10 ...
View Full Document
This note was uploaded on 02/27/2010 for the course CHEM 140 taught by Professor Wade during the Spring '10 term at Whitman.
- Spring '10