A new addition reaction of trialkyl phosphite and alkyl halide to nitrone

Synthetic Methods for Azaheterocyclic Phosphonates and Their Biological Activity

“…A catalytic amount of alkyl halide is sufficient for the reaction to occur, since additional alkyl halide is liberated during the phosphite addition (Arbuzov type dealkylation). As a matter of fact, when the added alkyl halide is different from the halide formed during the reaction, a mixture of the two corresponding phosphonopyrrolidines is obtained 94 …”

“…As a matter of fact, when the added alkyl halide is different from the halide formed during the reaction, a mixture of the two corresponding phosphonopyrrolidines is obtained. 180 One example of 1,4-addition was described under modified conditions. In the presence of a Lewis acid, ring contraction of 6H-1,2-oxazine 396 occurs with the formation of an R,β-unsaturated nitrone 397.…”

Total Synthesis of Deschlorocallipeltoside A

“…The completion of the synthesis of the core ( 23 ) of callipeltoside A is displayed in Scheme . The kinetically formed E lithium enolate of tert -butyl thiopropionate adds to aldehyde 16 to provide the Cram-type addition product 17 with 5:1 diastereoselectivity . Felkin−Ahn type addition to aldehyde 18 of the dienyl silyl ether 19 8 produced a single diastereomer 20 whose silyl ether 21 was subjected to CAN to liberate the C-13 hydroxyl group ( 22 ) for macrocyclization.…”