TiCl4 mediated preparation of (E)-non-conjugated homoallylic alcohols with α-substituted allylsilanes
摘要:
The allylation of various aldehydes with alpha-substituted allylsilanes in the presence of TiCl4 has been investigated. It has been shown that these reagents readily allow for good yields and high to excellent diastereoselectivities (up to >20:1) for a series of aldehydes, thereby providing a means of preparing non-conjugated (E)-homoallylic alcohols in a single step. (C) 2013 Elsevier Ltd. All rights reserved.
TiCl4 mediated preparation of (E)-non-conjugated homoallylic alcohols with α-substituted allylsilanes
摘要:
The allylation of various aldehydes with alpha-substituted allylsilanes in the presence of TiCl4 has been investigated. It has been shown that these reagents readily allow for good yields and high to excellent diastereoselectivities (up to >20:1) for a series of aldehydes, thereby providing a means of preparing non-conjugated (E)-homoallylic alcohols in a single step. (C) 2013 Elsevier Ltd. All rights reserved.
Piclavines A1 and A2 have been synthesised for the first time. The route is short with the key step being the reaction of a bicyclic N-acyl iminium ion with 3-trimethysilyl-1-decene. This convergent strategy gave exclusively compounds in which the pendant decenyl group was axial, as a 6:1 mixture of E:Z-alkene diastereoisomers. Reduction of the lactam carbonyl group gave a 6:1 mixture of piclavines A1 and
Various allylic acetates (1a-j) are silylated with hexamethyldisilane (Me3SiSiMe3, 2) in the presence of a catalytic amount of Pd(DBA)2 and LiCl at 100-degrees-C to afford the corresponding allylic silanes in high yields. In addition, (trimethylsilyl)tributylstannane (Me3SiSnBu3, 3) can be used for the silylation of aromatic allylic acetates 1g-j at room temperature.
Regioselection in the alkylation of trimethylsilylallyl anion - stereoselective synthesis of disubstituted alkenes
作者:K. Koumaglo、T.H. Chan
DOI:10.1016/s0040-4039(01)80008-3
日期:1984.1
Tsuji Yasushi, Kajita Satoshi, Isobe Shinya, Funato Masahiro, J. Org. Chem., 58 (1993) N 14, S 3607-3608