Comparison of the allylation reactions of aldehydes using allylstannanes with boron trifluoride etherate and boron trichloride
作者:Daniele Marton、Giuseppe Tagliavini、Michele Zordan、James L. Wardell
DOI:10.1016/0022-328x(90)85025-t
日期:1990.7
Reactions between allylstannanes, R2CH=CHCHR1SnBu3 (R1 = R2 = H (4); R1 = H, R2 = Me (5); R1R2 = (CH2)3 (6)) and aldehydes, RCHO (e.g. R = Et) in the presence of BF3 · OEt2 in CH2Cl2 at −78°C produce stereoselectively erythro-RCH(OH)CHR2CH=CHR1 (with one equivalent RCHO) and 4-OH-3-R1-5-R2-2,6-R2-tetrahydropyrans (with an excess of RCHO). In contrast, when BCl3 is used in place of BF3 · OEt2 the reactions
烯丙基锡烷之间的反应,R 2 CH = CHCHR 1 SnBu 3(R 1 = R 2 = H(4); R 1 = H,R 2 = Me(5); R 1 R 2 =(CH 2)3(6) )和醛类,在-78°C下在CH 2 Cl 2中在BF 3 ·OEt 2存在下,RCHO(例如R = Et)产生立体选择性赤型-RCH(OH)CHR 2 CH = CHR 1(具有一个等价的RCHO)和4-OH-3-R 1-5-R 2 -2,6-R 2-四氢吡喃(RCHO过量)。相反,当使用BCl 3代替BF 3 ·OEt 2时,反应生成氯化烯烃(均烯丙基氯和烯丙基氯)和4-Cl-3-R 1 -5-R 2 -2,6-的混合物R 2-四氢吡喃(3; X = Cl)。因此5,EtCHO和BCL 3(所有等摩尔)提供EtCHClCH 2 CH = CHME(51%,(ë)+(Ž)),EtCHClCHMeCH = CH