Alkylation of Benzothiazolines and the Stevens Rearrangement of the Resulting 2,3,3-Trisubstituted Benzothiazolinium Salts
作者:Kin-ya Akiba、Yoshio Ohara、Naoki Inamoto
DOI:10.1246/bcsj.55.2976
日期:1982.9
(3). The configuration of two alkyl groups on the nitrogen was assigned by NMR spectra and NOE measurement. In the Stevens rearrangement of 3 with lithium diisopropylamide ethyl group showed a much larger migratory aptitude (Et:Me≥20 :1) than methyl group irrespective of the configuration of 3, and cyclic ammonium ylide with planar π-type carbanion was proposed as an intermediate. 3 suffered nucleophilic
Nonacidic and Highly Chemoselective Protection of the Carbonyl Function. 3-Methylbenzothiazolines as a Base- and Acid-Resistant Protected Form for the Carbonyl Groups
groups by conversion into 3-methylbenzothiazoline derivatives with o-(methylamino)benzenethiol was described. With this method, 3-methylbenzothiazolines were conveniently obtained in excellent yields from various aldehydes and ketones. This method allows efficient protection and deprotection under mild and neutral conditions and affords protection of the carbonyl group against both basic and acidic conditions