Synthesis of unsymmetrical diallyl ketones: the palladium-catalyzed coupling of allyl halides with allyltin reagents in the presence of carbon monoxide

Concise and direct construction of cis-pyrano[4,3-b]pyran-5-one skeleton from glucal derivatives: synthesis of ent-4-deoxy-2,3-di-epi-dinemasone BC

“…Reaction of 2-deoxy-glucal 12 26 with AgNO 3 and NIS in CH 3 CN 27 gave 81% of the 2-iodoglucal 11, coupling of 11 with vinylstannane 13 28 in the presence of Pd(Ph 3 P) 4 and CuI 29 in a sealed carbon monoxide atmosphere [30][31][32][33][34][35] resulted in the formation of divinyl ketone 10 in 86%. Promoted by BF 3 ÁOEt 2 , 36 Nazarov cyclization 37-41 of divinyl ketone 10 furnished the desired cyclopentenone 9 in 62% as the only isomer.…”

Carbonylation

“…(5.6), by reaction of allyl chlorides and allyltin reagents in the presence of carbon monoxide and a palladium catalyst. (132) This type of reaction sequence has been extended to vinyl allyl ketones and provides, for example, a high-yield synthesis of egomaketone from prenyl chloride and 3-furanyltrimethyltin [Eq. (5.7)].…”

Access to carbon–carbon bonds

“…The coupling of allylic halides with allyltins in presence of carbon monoxide offers an interesting route to unsymmetrical diallyl ketones 486 . The experimental conditions are mild enough to avoid isomerization to conjugated ketones as well as further addition of the allyltin reagent to the carbonyl group.…”