✦ LIBER ✦

Stereoselective Cyclization of 4-Substituted 5-Hexen-1-ols and Related Compounds by Benzeneselenenyl Triflate

✍ Scribed by Inoue, Hirohumi ;Murata, Shizuaki ;Suzuki, Toshiyasu

Publisher: John Wiley and Sons
Year: 1994
Tongue: English
Weight: 953 KB
Volume: 1994
Category: Article
ISSN: 0947-3440
DOI: 10.1002/jlac.199419940910

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

Oxyselenylation of 4‐substituted 5‐hexen‐1‐ols 1 with benzeneselenenyl trifluoromethanesulfonate proceeds by intramolecular exo cyclization stereoselectively to give 3‐substituted trans‐ or cis‐2‐(phenylselenenylmethyl)tetrahydropyrans 3. Formation of the trans isomers is favored when the substituents contain alkyl or phenyl substituents in the 4‐position, whereas the cis isomers predominate when the substituents are alkoxyalkyl, alkoxyl, acyl, and hydroxyl. The mechanism of the trans and cis stereoselectivity is explained by steric and electronic effects in the phenylseleniranium intermediates, 7 and 8.

📜 SIMILAR VOLUMES

Stereoselective Synthesis of Steroids an

Stereoselective Synthesis of Steroids and Related Compounds. Part 7. 3-Substituted and 2,3-Disubstituted Cyclopentanones via an Asymmetric Tandem 1,4-Addition/Dieckmann Cyclization.

✍ Ulrich Groth; Wolfgang Halfbrodt; Aris Kalogerakis; Thomas Koehler; Paul Kreye 📂 Article 📅 2004 🏛 John Wiley and Sons ⚖ 91 KB 👁 1 views

ChemInform Abstract: A New Synthesis of

ChemInform Abstract: A New Synthesis of Substituted Imidazo[4,5-b]pyridinones by Reductive Cyclization of 4-Nitro-1H-imidazol-5-yl Di- and Tri-carbonyl Compounds.

✍ George Tennant; Christopher J. Wallis; George W. Weaver 📂 Article 📅 2010 🏛 John Wiley and Sons ⚖ 34 KB 👁 2 views

Thioalkylation of Enolates, III. Stereos

Thioalkylation of Enolates, III. Stereoselective Synthesis of Steroids and Related Compounds, II α-Thioalkylation of Zinc Dienolates to 4-Substituted 1-tert-Butoxy-7a-methyl-hexahydroinden-5-ones

✍ Groth, Ulrich ;Köhler, Thomas ;Taapken, Thomas 📂 Article 📅 1994 🏛 John Wiley and Sons 🌐 English ⚖ 484 KB

## Abstract α‐Alkylation of the α,β‐unsaturated ketone 1 at C‐4 has been achieved by thioalkylation of the corresponding zinc dienolate with α‐chlorosulfides of type 2. The desulfurization of the β‐(phenylthio) ketones 4 leads directly to the 4‐substituted hexahydroinden‐5‐ones 5. magnified image