310460-67-4Relevant academic research and scientific papers
Stereoselective N-acylation of a new chiral auxiliary compound; 3-phenyl-l-menthopyrazole
Kashima,Fukuchi,Takahashi,Hosomi
, p. 8305 - 8308 (1993)
As a new chiral auxiliary compound having a pyrazole ring system, the synthetic utility of (4R,7S)-3-phenyl-4-methyl-7-isopropyl-4,5,6,7-tetrahydroindazole (3-phenyl-l-menthopyrazole), which was prepared from l-menthone, was discussed.
Asymmetric borane reduction of ketones catalyzed by N-hydroxyalkyl-l-menthopyrazoles
Kashima,Tsukamoto,Higashide,Nakazono
, p. 983 - 990 (2007/10/03)
The equimolar mixture of N-(hydroxyalkyl)pyrazoles and borane formed boric ester complex, in which the remaining borane was stabilized by the adjacent nitrogen of thr pyrazole ring. The borane complex derived from the chiral pyrazoles such as 3-phenyl-l-menthopyrazole reduced p-methylacetophenone (21) enantioselectively. When (2'S)-2-(2'-phenyl-2'-hydroxyethyl)-3-phenyl-l-menthopyrazole ((2'S)-10b) was used, 21 was reduced into (S)-p-methylphenyl-1-ethanol (22) in moderate chemical and optical yields. Due to the inconvenience of the preparation and the lower optical yield, the use of N-(α-hydroxyalkyl)pyrazoles was unpromising for the enantioselective reduction of ketones by borane.
