Regioselective additions of electrophiles to olefins remotely perturbed. The carbonyl group as a homoconjugated electron donating substituent.

On the Reactivity of (7-Oxabicyclo[2.2.1]hept-5-en-2-ylidene)amines. Different Reaction Paths Leading to the Same Final Products

“…± Substituted 7-oxabicyclo[2.2.1]heptane derivatives 1 are important synthetic intermediates because these compounds show a broad spectrum of reactivity generally in a predictable regio-and stereocontrolled fashion [1]. In particular, remote controlled electrophilic addition to the endocyclic CC bond of the unsaturated derivatives 2 1 ) [2] [3] and nucleophilic addition to the carbonyl group of compounds 3 2 ) [4] have been considered in depth.…”

Synthesis and Diels‐Alder Reactivity of 5,6,7,8‐Tetramethylidene‐2‐bicyclo[2.2.2]octanol and ‐octanone. Selective Oxidations of the Corresponding Bis(irontricarbonyl) Complexes

“…-MS. (70 eV): 452 (OS), 424 (9), 396 (24), 368 (18), 340 (14). 312 (25), 284 (W), 282 (16), 258 (25), 256 (13), 229 (17), 198 (15), 176 (24) (5, 6,7,8-~etramethylidene-2-bicyclo[2.2.2]octanone)]iron (28) Method A. Freshly sublimed trimethylamine oxide (1 g, 13.3 mmol) was added to a stirred solution of 27 (0.5 g, 1.1 mmol) in anh. acetone (100 ml).…”

“…HZCEC(8)); 67.1 (d, 'Jc,H= 144, C(1)); 48.4 (d, ( t , 'Jc,H= 132, C(3)); attributions based on comparison with related systems, see [21] [22]. -MS. (70 eV): 172 (23), 144 (22), 130 (54), 129 (86), 128 (64), 127 (27), 115 (loo), 91 (25), 89 (20), 77 (32). 'Jc,H= 144, C(4)); 44.1 CizH120 (172.23) Calc.…”

“…H2C=C(6), H2C=C (7), H2C=C (8) 424 (9), 396 (24), 368 (18), 340 (14). 312 (25), 284 (W), 282 (16), 258 (25), 256 (13), 229 (17), 198 (15), 176 (24), 148 (30), 115 (30), 112 (100). Method A. Freshly sublimed trimethylamine oxide (1 g, 13.3 mmol) was added to a stirred solution of 27 (0.5 g, 1.1 mmol) in anh.…”

Optical resolution of 7‐oxabicyclo[2.2.1]hept‐21‐ene derivatives. Diastereoselectivity in the formation of cyanohydrine‐brucine complexes

“…We recently reported the preparation of two optically pure 7-oxabicyclo[2.2. llheptane derivatives, (+)-1 and (+)-2 [4]. Systems such as these can be viewed as 'naked sugars' since positions C(3), C (5), and C(6) can be stereospecifically functionalized with a variety of substituents; electrophilic additions to the C(5), C(6) double bond are highly stereoselective (51 [6], and electrophilic substitution of a H-atom at C (3) in 1 (and other related ketones) can also be highly stereoselective under either thermodynamic or kinetic control [7]. [9] is also reported.…”