[reaction: see text]. Upon treatment with n-BuLi at low temperatures, a variety of allyl 1,1-dichlorovinyl ethers 2 undergo rearrangement to furnish gamma,delta-unsaturated esters 3 after alcohol addition. Compounds containing quaternary centers (3e: R1 = H, R2, R3 = -(CH2)5-; 3f: R1 = H, R2 = CH3, R3 = (CH2)2CH(CH3)2) may be formed in high yield and under mild conditions utilizing this protocol. The
[反应:请参见文字]。在低温下用n-BuLi处理后,各种烯丙基1,1-二
氯乙烯基醚2经过重排以在加入醇后提供γ,δ-不饱和酯3。可以高收率形成含季中心(3e:R1 = H,R2,R3 =-(
CH2)5-; 3f:R1 = H,R2 =
CH3,R3 =( )2CH( )2)的化合物,在温和的条件下,使用此协议。该反应是立体特异性的,可用于制备δ(2,3)-β-C-糖苷和α,β-二取代的内酯。