5S*)-4-ethyl-5-methyl-2-(2-methylpropyl)-1,3-dioxolane (5) (trace component). Syntheses of optically active 1 and 3 were carried out by reacting pure enantiomers of 2,3-pentanediol with 3-pentanone or 2-methylpropanal. The preparation of pure stereoisomers of 2,3-pentanediol involved a novel key step for the synthesis of secondary alcohols: the reduction of a carboxylic ester by means of DIBAH and in situ alkylation
通过
SPME-GC / MS分析了两个真实的Triatominae亚科的臭虫,巴西的Triatoma brasiliensis和Triatoma infestans的后胸骨挥发物。发现了两组新的
天然产物:(4 S,5 S)-和(4 R,5 R)-
2,2,
2,4-三乙基-5-
甲基-
1,3-二氧戊环(1)(主要成分)和(4 S *,5 S *)-
2,4-
二乙基-2,5-二
甲基-
1,3-二氧戊环(2)(痕量组分),(2 R / S,4 S,5 S)-以及(2 R / S,4 R,5 R)-4-乙基-5-
甲基-2-(
1-甲基乙基)-
1,3-二氧戊环(3)(次要成分),(2 R / S,4 S *,5 S *)-4 -乙基-5-
甲基-2-(
1-甲基丙基)-
1,3-二氧戊环(4)(痕量组分)和(2 R / S,4 S *,5 S *)-4-乙基-5-
甲基-2-(
2-甲基丙基)-
1,3-二氧戊环(5)(