Synthesis of medium-sized lactones from siloxy alkynes via ring expansion
作者:An Wu、Wanxiang Zhao、Jianwei Sun
DOI:10.1016/j.tet.2020.131163
日期:2020.12
topic in organic synthesis due to the disfavored kinetic and thermodynamic features. Herein we detail an efficient intermolecular process using siloxyalkynes as substrates and oxetene ring expansion as the key strategy. With extension to a new silyl-masked alkyne, this reaction now features a broad scope, high efficiency, and mild conditions.
The present invention relates to a method of enantioselective addition to enones, including: reacting R
3
(CH
2
)
p
CH═CR
5
C(═O)Y(CH
2
)
q
R
4
with R
6
ZnR
7
in the presence of a compound represented by the following formula (I) and a transition metal catalyst,
in which Y, p, q, R
1
, R
2
, R
3
, R
4
, R
5
, R
6
and R
7
are defined the same as the specification. Accordingly, the present invention can perform asymmetric conjugate addition in high yields and enantioselectivity.
Conversion of lactones to the higher homologous α, β-unsaturated lactones v/a hypervalent iodine oxidation of 1-trimethylsilyloxy-2-oxa[n.1.0] cycloalkanes