- Regio- and stereoselective synthesis of the enantiomers of monoterpene-based β-amino acid derivatives
-
The regio- and stereospecific addition of chlorosulfonyl isocyanate to cis-δ-pinene enantiomers has furnished monoterpene-fused β-lactams. The observed regioselectivity can be explained by ab initio DFT modeling of transition state structures. In contrast with the less reactive α-pinane-fused β-lactam 4, the resulting β-lactams 5 and 13 containing an amino group connected to a secondary carbon possess similar reactivity to the cycloalkane-fused analogues and can be easily converted to the β-amino acid and its protected derivatives. The base-catalyzed isomerization of the cis-amino ester afforded the corresponding trans-amino ester in moderate yield.
- Szakonyi, Zsolt,Martinek, Tamas A.,Sillanpaeae, Reijo,Fueloep, Ferenc
-
p. 2442 - 2447
(2008/03/13)
-
- Syntheses and reactions of new optically active terpene dialkyl diselenides
-
The reaction of sodium diselenide with optically active alkyl tosylates or chlorides is found to be a useful method for the synthesis of optically active dialkyl diselenides. Optically active monoterpene diselenides derived from menthane, carane, pinane,
- Scianowski, Jacek,Rafinski, Zbigniew,Wojtczak, Andrzej
-
p. 3216 - 3225
(2007/10/03)
-
- Rearrangement of Pinane Derivatives. Part 8. Deamination of 2αH-Pinan-3α-ylamine
-
Solvolysis of 2αH-pinan-3α-yl toluene-p-sulphonate has been shown to proceed with concomitant 1,2-hydride shift to give the pinan-2-yl carbocation.Contrary to earlier reports, this species reacts normally to give, in good yield, pinan-2-yl substitution products.In contrast the pinan-3-ylamines react via a similar route, but give much smaller amounts of pinan-2-yl products.The usual reasons for differences between solvolysis and deamination (i.e. the intermediacy of diazonium ions and/or high-energy ions) can be discounted, and possible reasons for the differences in behaviour are discussed.
- Giddings, Rodney M.,Jones-Parry, Richard,Salmon, J. Roger,Whittaker, David
-
p. 725 - 728
(2007/10/02)
-