The reaction of crotyltrialkylstannanes (1) with aldehydes in the presence of BF3,OEt2, produces the corresponding erythro homoallyl alcohols (2) predominantly regardless of the geometry of the double bond. Further, the Lewis acid mediated reaction exhibits the enhanced Cram selectivity in comparison with other allylic organometallic reactions which proceed in the absence of Lewis acids. Use of AlCl3-i-PrOH
The reaction of but-2-enyltributylstannane with certain aldehydes in the presence of AlCl3–PriOH produces the α-adduct (3) either predominantly or exclusively, while the reaction in the presence of ordinary Lewis acids, such as TiCl4, SnCl4, and BF3·OEt2, affords the γ-adduct (2) exclusively.
Process for preparing predominantly Z-substituted allylic alcohols
申请人:SUMITOMO CHEMICAL COMPANY, LIMITED
公开号:EP0029603A1
公开(公告)日:1981-06-03
Process for preparing predominantly Z-substituted allylic alcohols of the formula I
wherein R1 is a straight or branched C1-C25 alkyl group optionally bearing at least one substituent and/or at least one unsaturated linkage and R2 is a hydrogen atom or a methyl group, which comprises reacting a vinyl epoxide of the formula II
wherein R2 is as defined above with an organolithium compound oftheformula III
wherein R1 is as defined above; particularly, process for preparing a-santalol oftheformula:
which comprises reacting 3-methyl-3,4-epoxybutene-1 with 3-lithiomethyl-2,3-dimethyltricyclo(2.21.02,6 heptane.
式 I 主要为 Z 取代的烯丙基醇的制备方法
其中 R1 为直链或支链 C1-C25 烷基,可选择带有至少一个取代基和/或至少一个不饱和连接基,R2 为氢原子或甲基,该工艺包括使式 II 的乙烯基环氧化物与式 III 的有机锂化合物反应
其中 R2 如上定义,与式 III 的有机锂化合物反应
其中 R1 如上定义;特别是制备式 a-山梨醇的工艺:
其中包括将 3-甲基-3,4-环氧丁烯-1 与 3-硫代甲基-2,3-二甲基三环(2.21.02,6)庚烷反应。
Regioreversed addition of crotylmagnesium chloride to carbonyl compounds in the presence of aluminum chloride
作者:Yoshinori Yamamoto、Kazuhiro Maruyama
DOI:10.1021/jo00157a046
日期:1983.5
RAXMANKULOV, D. L.;KANTOR, E. A.;ROMANOV, N. A.;MUSAVIROV, R. S., OSNOV. ORGAN. SINTEZ I NEFTEXIMIYA, YAROSLAVL, 1982, N 16, 47-57
作者:RAXMANKULOV, D. L.、KANTOR, E. A.、ROMANOV, N. A.、MUSAVIROV, R. S.