Erythroselective aldol condensation of amine Free 2-t-butyl-5-methyl-2-phenyl-1,3-dioxolan-4-one lithium enolate synthesis of the ethyl acetolactate enantiomers
摘要:
Generated by halogen metal exchange, the sterically hindered 2-t-butyl-5-methyl-2-phenyl -1,3-dioxolan-4-one lithium enolate reacts in an erythroselective way with acetaldehyde. Separation of the resulting diastereomers, followed by alcoholysis lead to the corresponding enantiomerically pure diols.
A One‐Pot Two‐Step Enzymatic Pathway for the Synthesis of Enantiomerically Enriched Vicinal Diols
作者:Pier Paolo Giovannini、Michel Müller、Francesco Presini、Serena Baraldi、Daniele Ragno、Graziano Di Carmine、Christian Jacoby、Giovanni Bernacchia、Olga Bortolini
DOI:10.1002/ejoc.202001542
日期:2021.2.12
this report a ThDP‐dependent lyase (Ao : DCPIP OR) and a NADH‐dependent reductase (AAR) have been consecutively employed in two steps without intermediate work‐up and purification, affording enantiomericallyenriched 1,2‐diols in good yield (up to 78 %). The reductase cloning and overexpression is herein reported for the first time.
Enzymatic Chemoselective Aldehyde-Ketone Cross-Couplings through the Polarity Reversal of Methylacetoin
作者:Giovanni Bernacchia、Olga Bortolini、Morena De Bastiani、Lindomar Alberto Lerin、Sabrina Loschonsky、Alessandro Massi、Michael Müller、Pier Paolo Giovannini
DOI:10.1002/anie.201502102
日期:2015.6.8
α‐hydroxy ketones through the rare aldehyde–ketone cross‐carboligation reaction. Unprecedented is the use of methylacetoin as the acetyl anion donor in combination with a range of strongly to weakly activated ketones. In some cases, Ao:DCPIP OR produced the desired tertiary alcohols with stereochemistry opposite to that obtained with other ThDP‐dependent enzymes. The combination of methylacetoin as acyl anion