反应详情

1.40 g (5.0 mM) of (-)-(4aR,10aR)-3,4,4a,5,10,10a-hexahydro-6-methoxy-4-methyl-9-methylthio-2H-naphth[2,3-b]-1,4-oxazine are dissolved in 50 ml of acetone and cooled to 0°. 2.75 ml (5.5 mM) of 2N ethereal hydrochloric acid are subsequently added whilst stirring. The precipitated salt is filtered off and washed with ether. (-)-(4aR,10aR)-3,4,4a,5,10,10a-hexahydro-6-methoxy-4-methyl-9-methylthio-2H-naphth[2,3-b]-1,4-oxazine hydrochloride is obtained (m.p. 237°-239°). Recrystallisation from acetone/ether, with the rotation value [α]D20 =-117.4° [c=0.52; methylene chloride/methanol (1:1)].

1. temperaturecooled to 0°
2. filtrationThe precipitated salt is filtered off
3. washwashed with ether