The reaction with methyl propargyl ether affords one regioisomer resulting from the HOMO dipolarophile-LUMO dipole interaction, which has largest coefficients on the carbon distal to the carbonyl group of the carbonyl ylide and on the methyl propargyl ether terminal alkyne carbon.
22.
Propargyl substituted bislactim ethyl ether is generated by using Sch�llkopf chiral auxiliary bis lactam ether with n-BuLi, THF, and 3-halo-1-9trimethylsily1 )-1-propyne and extracting the trans-isomer of the propargyl-substituted bislactim.
23.
Propargyl substituted bislactim ethyl ether is generated by using Sch�llkopf chiral auxiliary bis lactam ether with n-BuLi, THF, and 3-halo-1-9trimethylsily1 )-1-propyne and extracting the trans-isomer of the propargyl-substituted bislactim.
24.
The 20 carbon frame is constructed from several pieces : propargyl alcohol ( C1, C2, C14 ), propionaldehyde ( C13, C12, C18 ), isobutyric acid ( C15, C16, C17, C11 ), Trimethyl ( phenylthiomethyl ) silane ( C10 ), 2-bromobenzaldehyde ( C3 to C9 ), diethylaluminum cyanide ( C19 ) and trimethylsilylmethyl bromide ( C20)
