Received February 25, 1983 The palladium-catalyzed reaction of a variety of halo ketones or halo aldehydes with acetonyl- and allyltin reagents gives cyclic ethers in good yields. Oxiranes, oxetanes, and tetrahydrofurans can be obtained under mild reaction conditions. The use of palladium catalyst containing chiral monophosphine ligands gave a small enantiomeric excess (up to 19%) of a chiral oxirane from an a-halo ketone. The allyl- and acetonyloxirane products tend to undergo further transformations in prolonged reactions: allyloxiranes rearrange to a-allyl aldehydes and acetonyloxiranes dehydrate to give substituted furans. The mechanism of the reaction appears to involve addition of the organotin ligand to the carbonyl, followed by palladium(II)-catalyzed cyclization of the tin alkoxides.
ASJC Scopus subject areas
- Organic Chemistry