Stereoselective synthesis of cis-fused chlorinated bicyclic ethers via CAN-mediated ring-opening of cyclopropyl sulfides

✍ Scribed by Yoshiji Takemoto; Toshiro Ibuka; Hiroki Hayase; Akiko Iwanaga; Saori Yamagata; Chuzo Iwata; Tetsuaki Tanaka

• Publisher: Elsevier Science
• Year: 1998
• Tongue: French
• Weight: 243 KB
• Volume: 39
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(98)01641-4

✦ Synopsis

A facile method for synthesizing 3IS-chlorinated 2,6-disubstituted tetrahydropyrans is described. Introduction of a chloride to 2~-substituted and 2[~, 4~-disubstituted 3-oxabicyclo[3.1.0]hexyl phenyl sulfides proceeded efficiently by a CAN-mediated oxidation to give 3~-chlofinated tetrahydropyrans stereoselectively and in good yields, while the CAN-oxidation of 2~,,4[]-disubstituted 3-oxabicyclo[3.1.0]hexyl phenyl sulfide afforded the 3[]-chlorinated tetrahydropyran as a minor product. However, by tuning the aryl group of the sulfide, the desired 2~, 3[~,6~-chlorinated product was obtained in good yield. The following silane-reduction of the bicyclic chlorinated acetal gave the cis-fused chlorinated bicyclic ether, where all substituents are oriented on the same side.