Premium
A convenient and diastereoselective route to homoallyl alcohols: Addition of ( z )‐ or ( e )‐alkenyl‐dimethoxyboranes to aldehydes
Author(s) -
Fujitta Katsuramaru,
Schloser Manfred
Publication year - 1982
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19820650415
Subject(s) - chemistry , benzaldehyde , borane , pericyclic reaction , stereoselectivity , medicinal chemistry , stereochemistry , aldehyde , adduct , organic chemistry , catalysis
( Z )‐2‐Butenyl‐dimethoxyborane adds smoothly to propanal and benzaldehyde to afford the homoallyl alcohols ( R *, R *)‐ 1 and ( R *, R *)‐ 2 , In contrast ( E )‐2‐butenyl‐dimethoxyborane leads to adducts having the ( R *, S *)‐configuration. Dimethoxy‐( Z )‐2‐pentenylborane, dimethoxy‐( Z )‐(2‐methyl‐2‐butenyl)borane and (2 Z ,4 E )‐or (2 E ,4 Z )hexadienyl‐dimethoxyborane, treated with propanal, give ( R *, R *)‐ 3 , ( R *, R *)‐ 4 , ( E ),( R *, S *)‐ 5 and ( Z ),( R *, R *)‐ 5 , respectively. A transition state model implying a pericyclic electron motion is in perfect agreement with the regio‐ and stereoselective outcome of these borane reactions.