Preparation of sec. or tert. alcohols
申请人:Bayer Aktiengesellschaft
公开号:US05223633A1
公开(公告)日:1993-06-29
A process for the preparation of a compound of the formula ##STR1## which comprises deprotonating a carbamate of the formula ##STR2## in an inert solvent with a selective base, in the presence of a chelate-forming diamine to give a compound of the formula ##STR3## and then reacting III in an inert solvent, either with an achiral electrophile of the formula (IV) or (V) or with an optionally prochiral electrophile of the formula (VI) ##STR4## and in the case in which R.sup.1 represents an electrofugic leaving group, optionally again electrophilically substituted with the formation of an acyl anion and renewed deprotonation, and in a last step, solvolytically removing the protecting group --CO--NR.sup.10 R.sup.11.
制备公式##STR1##化合物的过程包括在惰性溶剂中用选择性碱去质子化公式##STR2##中的氨基甲酸酯,在螯合形成的二胺存在下得到公式##STR3##化合物,然后在惰性溶剂中将III与公式(IV)或(V)的无手性亲电试剂或公式(VI)的可选择性非手性亲电试剂反应,如果R.sup.1代表一个电子亲离基团,则可以选择性地再次通过亲电取代形成酰负离子和再次去质子化,最后,在最后一步中,溶解去除保护基--CO--NR.sup.10 R.sup.11。