ABSTRACT Submission of racemic, cis-fused cyclopenteno-1,2,4-trioxanes (1 and 1-ent) to catalytic amounts of K2OsO4 and (DHQD)2PHAL and 1.2 equivalents of N-methylmorpholine N-oxide in aqueous acetone at 20°C (hybrid AD-mix-β) for 2 h... more
ABSTRACT Submission of racemic, cis-fused cyclopenteno-1,2,4-trioxanes (1 and 1-ent) to catalytic amounts of K2OsO4 and (DHQD)2PHAL and 1.2 equivalents of N-methylmorpholine N-oxide in aqueous acetone at 20°C (hybrid AD-mix-β) for 2 h gave the (-)-enantiomer, 1-ent (ee 95%) in 30% yield. The same reaction, but with (DHQ)2PHAL, (hybrid AD-mix-α) afforded the (+)-enantiomer, 1 (ee 95%) in 25% yield after 2.7 h reaction. Similar, efficient kinetic resolution of the racemic di-p-fluoro analogues (2 and 2-ent) was also achieved with the same reagents.
185. A Practical Synthesis of (2S,3R)-3-Amino-2-methylpentanoic ... L-Aspartic acid by successive N-tosylation, anhydride formation, and reduction was converted into (3S)-3-(tosylamino)butano-4-lactone (4). Electrophilic methylation of 4,... more
185. A Practical Synthesis of (2S,3R)-3-Amino-2-methylpentanoic ... L-Aspartic acid by successive N-tosylation, anhydride formation, and reduction was converted into (3S)-3-(tosylamino)butano-4-lactone (4). Electrophilic methylation of 4, subsequent iodo-...
Abstract The three dihydronaphtho [1, 2, 4] trioxines 9–11 have been synthesized and two of them converted to the five carbamate and ester derivatives 12–16 (Schemes 1 and 2). The resulting new trioxanes together with two already known... more
Abstract The three dihydronaphtho [1, 2, 4] trioxines 9–11 have been synthesized and two of them converted to the five carbamate and ester derivatives 12–16 (Schemes 1 and 2). The resulting new trioxanes together with two already known and ascaridole (7) were tested ...
... of freshly purified DMPO (80 ml) to a soln. of the reactants in 2-methoxyethanol(80 ml) [6]. The final concentrations of the various reactants were RB: 4 mM, 1: 10 mM, DMNP: 60 mM, TENF: 10 mM, F: 10 mM, EC: 10 mM, F: 10 mM. ... [I41... more
... of freshly purified DMPO (80 ml) to a soln. of the reactants in 2-methoxyethanol(80 ml) [6]. The final concentrations of the various reactants were RB: 4 mM, 1: 10 mM, DMNP: 60 mM, TENF: 10 mM, F: 10 mM, EC: 10 mM, F: 10 mM. ... [I41 I. Saito, T. Matsuura, K. Inoue, J. Am. Chem. ...
Page 1. HELVETICA CHIMICA ACT,% Vo1. 59. yasc. 7 (1976) - Nr. 251 23.55 251. The Reaction of Difluorocarbene with Bicyclo[2.2.2]octadiene by Charles W. Jefford, Arlette Delay, Timothy W. Wallace and Ulrich Burger Department ...
... by Charles W. Jefford*, Danielle Jaggi, John Boukouvalas and Shigeo Kohmoto Department of Organic ... of the fleeting nature of the zwitterion or perhaps the absence of any particular nucleophilic ... J . P . Saulnier and A. Pinto for... more
... by Charles W. Jefford*, Danielle Jaggi, John Boukouvalas and Shigeo Kohmoto Department of Organic ... of the fleeting nature of the zwitterion or perhaps the absence of any particular nucleophilic ... J . P . Saulnier and A. Pinto for performing the NMR experiments and Ms. A . D ...
