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Stereoselective Synthesis of Alcohols, XXVII. Addition of (α‐Chlorocrotyl)boronates to Aldehydes
Author(s) -
Hoffmann Reinhard W.,
Dresely Stefan,
Lanz Joachim W.
Publication year - 1988
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19881210826
Subject(s) - chemistry , aldehyde , stereochemistry , stereoselectivity , organic chemistry , catalysis
Abstract ( Z )‐(α‐Chlorocrotyl)boronates 3 add to nonchiral aldehydes to give homoallyl alcohols 5 with a syn ‐β‐positioned methyl group and an ( E )‐chloroalkenyl unit. The diastereoselectivity in favour of 5 is around 90%. The corresponding ( E )‐(α‐chlorocrotyl)boronates 6 similarly lead to homoallyl alcohols 7 with an anti ‐β‐methyl group and a ( Z )‐chloroalkenyl unit, the diastereoselectivity being > 95%. Using optically active boronate 6 the resulting homoallyl alcohols 7 are obtained with > 95% e.e.