Efficient oxidation of phenyl groups to carboxylic acids with ruthenium tetraoxide. A simple synthesis of (R)-.gamma.-caprolactone, the pheromone of Trogoderma granarium

Abstract

We thank Professor W. D. Wulff for helpful and stimulating discussions. Supplementary Material Available: A summary table of the results of the benzannulation reaction study (eqs 1-2), full experimental for 2, 8-9, 20, 54-64, characterization of 26, 28-31, 33,[39][40][42][43] and 45, and NMR spectra of 12, 33, 65c, 70, 74, and 75 (24 pages). Ordering information is given on any current masthead page.

Efficient Synthesis of Cyclopropane‐Fused Heterocycles with Bromoethylsulfonium Salt

“…The synthetic utility of the methodology is illustrated through a range of functional group transformations of several of the [3.1.0] pyrrolidines. For example, oxidative cleavage of the Ph group [34] in 8a gave pyrrolidine 13 which is both an α-and a β-amino acid derivative (Scheme 4). [35] Deprotection and oxidation of 6l gave the conformationally locked glutamic acid analogue (Scheme 5).…”

Cyclopropyl Building Blocks for Organic Synthesis, Part 100. Advanced Syntheses of Cyclopropylideneacetates –Versatile Multifunctional Building Blocks for Organic Synthesis

“…Drying of the organic phase over MgSO 4 and removal of the solvent under vacuum afforded 3-Me as colorless crystals; yield: 5.35 g (99%); 1 H NMR (CDCl 3 , 250 MHz): d ¼ 1.41 ± 1.50 (m, 2H, Cpr-CH 2 ), 1.66 ± 1.75 (m, 2H, Cpr-CH 2 ), 3.83 (s, 3H, CH 3 ); 13 C NMR (CDCl 3 , 62.9 MHz): d ¼ 5.5 ( À , Cpr-C), 9.7 ( À , Cpr-C), 52.9 ( þ , CH 3 ), 114.7 (C quat , Cpr-C), 139.1 (C quat , Cl-C), 162.7 (C quat , C¼O). The additional experimental data are identical to those reported in literature.…”

“…The product 6 was pure enough for direct transformation to the more stable mesylate 7, [11] which was obtained in 92% yield. Oxidative cleavage of the phenyl group with in situ generated ruthenium tetroxide under conditions developed by Sharpless et al, [12] but with 7 equivalents of orthoperiodic acid [13] as the cooxidant, led to 2-(1'-mesyloxycyclopropyl)acetic acid (8) in 96% yield (74% overall from 1), after crystallization from diethyl ether (Scheme 2).…”

Ruthenium (VIII) mediated oxidation of some aliphatic and alicyclic ketones by periodate-ruthenium (III) system in aqueous HClO4 medium

“…This species is not involved in the rate determining enolization of ketones and has the only role of abstracting a hydride ion from the enol, thus assisting the oxidation process. The in situ generation of Ru(VII1) species from Ru(III)-IO,~ in acid solutions has the potential to be useful in synthetic methods [41]. because of the difficulty in handling the commonly used.…”